Clijsters and Capriati have fewer slams than Sanchez Vicario. I certainly hope you don't consider Sanchez Vicario the better tennis player.
I am not saying that applies to Sharapova vs Azarenka or not, but in some cases the inferior player does even up with more big titles. Be it through quality of competition, luck, timing, benefitting from someone being stabbed (Sanchez), benefitting from doping for awhile (Sharapova), etc...
Sanchez Vicario is actually a better player than Capriarti, and slightly better than Clijsters she just belongs to a completely different context. 14 GS titles combined (singles, doubles, mixed doubles), 12 GS finals. Btw she has won her first French Open years before Seles was stabbed, and was one of the few who could actually cause Graf troubles.
Once again, Sharapova did not benefit from doping. Meldonium is a placebo with no proven effects. There is a lot on this in internet. The reason why it was banned was a political one. It was not banned until 01.2016 thus it was completely legal to take it. Serena, on the other hand, has a verified record of using a banned substance even though within TUEs:
Serena Williams' Therapeutic Use Exemptions (TUEs)
Date for use/Date given/Substance
*Oct 2010 - Mar 2011/23 Dec/Hydromorphone
*Dec 2010/23 Dec/Oxycodone
*Nov 27-Dec 1 2010/23 Dec/Methylprednisolone
*12-19 Mar 2014/13th Mar/Prednisone
*21-30 Mar 2014/2 Apr/Prednisone
*7-21 May 2014/8 May/Prednisone
*10-17 Nov 2014/3 Dec/Prednisone, Oxycodone
*5-10 June 2015/8 Jun/Prednisolone
Azarenka is a great player for sure, but it's probably makes more sense to compare her with Kerber tbh.