There is two arguments with sheilds, one is hp and the other is cost, on a cost/hp scale the list is reversed.
T2 sheilds come up quicker, you can also do sheilds micro and turn off sheilds so they don't get splash damage then turn them on when others turn off from damage, takes alot of work but works the best.
Best to counter experimental with what they are weak at, if no t3maa use air,big it's a air use asf, etc