Well I mean he only won 4 last year, including two 500s and a 250. A lot of Connors' 109 titles were below Masters level (81) so that's not a knock on Fed. Roger only has 46 titles below Masters in comparison.
He should enter more 500s moving forward. Basel & Halle are not enough unless he expects himself to play till 41. I know he played Rotterdam to get the #1 but it's a good fit for him moving forward if he skips Miami which he should. Then I don't know why he doesn't play Tokyo. He skipped Dubai but plays there often, competition hasn't been as great but if Novak comes back to I don't like Roger's chances there. Course right now Stuttgart is the only 250 he plays, if he wants to add one there's plenty of options, I'd be guessing Qatar but Novak might make that a waste. If playing 3 weeks in a row isn't out of the question late in the year, Stockholm would be a great vulturing opportunity inbetween Shanghai and Basel. Especially if he starts skipping USO which he might.
As for 2019, I see no Slams, hoping he wins Indian Wells as I'll be going this year but Novak might be too strong. Gotta think he wins at least one of Stuttgart/Halle and Basel, so I'll throw 3 and say 102.