The myth of Clayray lives on with this thread. 3-2 in Clay finals for his career and I'm pretty sure these were all in the Nadal vacuum period of 2015-2016.
His and Djokovic's ELO's would have been massively boosted by cheap wins over Nadal during this period.
Murray is not even close to Thiem. He's a pusher with no serve game on clay. I do think the clay field was exceptionally weak (outside of the Big 3) during Murray's relevant career (2016 and before). Wawrinka was undoubtedly formidable, but he's way too elevated because of his match up with Djokovic.
Getting into the details of Murray appearances in actual clay court events he never made a final until 2015 and Kohlschreiber was an arch foe at Bavaria and Madrid with others like Lukas Rosol. Beating Nadal in 2015 Madrid final is a paper tiger. In 2016 Murray had trouble with the likes of Stepanek in Madrid and his win over Djokovic in the Rome final while somewhat impressive after losing to Djokovic in Madrid, both players were tired and Djokovic might not have been dealing with a full deck of cards with his serve game since he clearly had started having elbow troubles by the time of 2016 Miami encounter with Thiem where he was double faulting like crazy. Djokovic got his 4th slam in a row that year at RG, but he was great enough to get by while not at his absolute best. Murray was extremely inefficient in his run to the 2016 RG final and the 2017 draw and SF encounter with Wawrinka was the culmination of one of the weakest halfs seen at RG in recent times. But it has to be said that if Murray had not botched his 2016 run so badly he might have been able to pull off the upset of Djokovic; Murray was clearly physically spent by sometime in the 3rd set and pretty much rolled over the rest of the way in the final.
The main ingredient needed to win the biggest event on clay and the Masters when they were one week events is a great serve game on clay (to go with a clay court game, sorry Andy Roddick, John Isner, et al.) This is something Murray really did not have especially with his abysmal 2nd serving. Sure with Lendl riding him at times he had a little bit of offense at his best moments, but what he did pull off mainly in 2016 it has to be remembered ultimately ended his career at the top of the game. Heck even the run Djokovic was doing from 2015 into 2016 took a big toll on him and he fell apart for two years as a result (elbowovic.)
If you go back and look at some revered clay court players like Muster they only really managed one great RG run because they're serve games were quite weak and they had too many extended matches. Courier and Kuerten were the earliest players where we can confirm via stats that they had a fine serve game on clay. Nadal obviously has plenty of offense on clay.
To be clear, Murray would not have fared very well playing lots of tournaments on clay. He didn't play them for a reason. Starting in 2008 outside of Masters 1000s on clay he played:
Barcelona 2008 Mario Ancic (WC) Rank 51 Elo 2108 (+9) d. [GBR] Andy Murray (7) Rank 19 Elo 2135 (-10)
6-4 6-4
Barcelona 2012 QF Milos Raonic (11) Rank 25 Elo 2047 (+16) d. [GBR] Andy Murray (2) Rank 4 Elo 2342 (-15)
6-4 7-6(3)
2014 Davis Cup WG QF Fabio Fognini Rank 13 Elo 2096 (+15) d. [GBR] Andy Murray Rank 8 Elo 2315 (-15)
6-3 6-3 6-4
2015 Munich Clay F Andy Murray (1) Rank 3 Elo 2324 (+3) d. [GER] Philipp Kohlschreiber (5) Rank 26
7-6(4) 5-7 7-6(4) - Barely beats the elderly Kohly
Murray would have been chewed up and spit out if he played in real clay court tournaments and not just mandatory masters events where tons of hard/fast court players were in the draw.
So just based on that here is who in the current game I'd rate over Murray (I'd give Murray 2016 a shot in a match in the right circumstances, but talent and with so much pushing what he was doing was unsustainable.)
1. Nolebot (that better serve since 2021 quite helpful on clay especially)
2. Sinner (Murray's pushing would be absolutely destroyed)
3. Alcaraz (another mauling)
4. Medvedev (with Medly's reduced serving due to string changes the last two seasons he is the Murray comparable, but he's not subjected himself to a lifetime of pushing and used to have a serve so he's much, much less physically hampered than Murray. I'll be biased and give Medvedev the nod given his career is not yet complete, but a healthy Medvedev has more potential than Murray on clay. A match between the two in the right conditions might have been a career ender for Murray.)
5. Zverev (also suffers from the love of pushing, but has a serve and Murray never could have hung with Nadal like Zverev did in 2022 SF.)
6. Ruud (way better clay court player)
7. Rublev (can't push like Murray and has an equally weak 2nd serve, but much better first serve. Probably beats Murray in a match eventually running Murray down with his offense, as he just did to Alcaraz all too recently
)
8. Tsitsipas (completely outclasses Murray)
9. Rune (its not even going to be close and would have run Murray more ragged than any player with his junk balling)
10. Shelton (this is probably more questionable than Medvedev and Rublev who also don't have clay court pedigrees, but Shelton is the best left hander in the game since Nadal and better than Nadal's toughest southpaw foes (Verdasco) and Ben can emulate the Nadal shot patterns. Right now it would be a hilarious match to see. In the long run Shelton probably will be better on clay.)
11. Khachanov (questionable, but he gave Murray a good match at 2017 RG and is a brutal slam player right now. He's also a heavy spin player not unlike Nadal and I doubt Murray would fare well)
12. Struff (well on his day he ticks all the boxes and absolutely could have hit through Murray)
The rest of Murray's betters:
1. Thiem
2. Matteo Berrettini (a stretch, but I suspect his serve and clay court skills would have been a challenge for Murray and we've never quite seen Matteo at his best due to worse injury problems then Murray)
3. Federer (pretty sure there would have been some finger wags)
4. Del Potro (gimp on gimp action, but Delpo ticks the box with his serve)
5. Cilic (old Cilic versus Clayray might have been close)
6. Berdych (younger Berdych probably would be a close one)
7. Almagro (he'd have to be at this best)
8. Soderling
9. Fernando Gonzalez (peak to peak might have been fun for old Clayray getting abused by power in its rawest form)
10. Meltzer (another fun one peak to peak)
11. Kohlschreiber (peak Kohly for the win, Murray barely beat the much older Kohly at 2014 RG 12-10 in the 5th set since there was no tiebreaker.
)
I think the myth of Clayray is best summed up in his matches with Djokovic. Murray did a much better job of managing his 2015 run and their SF was a five set clash probably setting up Novak for the fall to Wawrinka in the final. 2016 Clayray got through to the Madrid Final and lost narrowly to Djokovic and then cruised through Rome just a week later straight setting everyone with ease (an impressive run.) Unfortunately despite this efficiency, 2016 Roland Garros opened with a couple inexplicable five set bungles which ultimately had him out of gas by the final. He might have won if he'd come out strong at RG. I suspect that this was just too much tennis for Murray. Wawrinka to my recollection was alright in 2016, but struggling to find form coming into the tournament and his US Open win was a real surprise. I suspect that Murray actually was a bit of a matchup problem for Novak and impressively he had him beat at 2011 Rome Masters, but then started double faulting at 5-4 30-15 in the 3rd set. This according to many was during Djokovic's peak run (I'd say it was his peak movement based run, but much better player in 2015-2016.)