Yeah you should pick your team with those things in mind, however, reserves are for injured players, not because they've been dropped or rested.
in my views reserve player are for forced change. When We pick a player from squad and if he doesn't play few matches then its our fault as we have made wrong prediction. But if player is replaced from Squad after series has started then fantasy manager should get chance to replace their player especially when 40% (2 matches) of game is still left.
Umesh yadav has scored 113 points and i don't think my reserved player will score more than 113-120 points. So it won't effect my score much even if umesh is not replaced but i feel sorry for the guy who has pick Umesh as Captain.