Absolutely, we have to adapt the tactics towards our squad members..but the main tactic used are not always give you the edge to all the games,we might still lose some games..especially if we are using the lower tier teams, fighting the top teams will cause our teams **** D: we must keep adapting to opponent tactics
It happens to me several times, as im currently using sunderland..and u know they dont have the best squad in the league

leading 2-1 in a match against chelsea at 76 mins..then the AI manager switched to 3-2-5, brigingin in their wingers and additional strikers..and happened those five forwards are:
Drogba Cassano
Malouda lampard ribery (no kidding! they bought ribery T_T)
ended up in 2-3 loss on my side..
Also the thoughts of keep changing the tactics will cause your squad to be unsettled in the play style,causing confusion