I've no problem with Del Piero playing as long as Juve use an appropriate gameplan i.e. base the whole game on getting the ball high up the pitch and winning freekicks.
Just don't expect Del Piero to do anything much in open play.
Iaquinta is a bit different in that he can actually move well of the ball and open up the pitch for other to take advantage of.
Matri doesn't convince me.
Toni is what he is. If you play him, you have to commit to long ball and consistently get players close to him to take advantage of the high balls he wins.
I agree there, Iauinta's running off the ball is more superior, but he is working less and whining mopre these days. On his day, he is way better than Toni and Matri, and both are compatible to play next to him. Are any of those capable of slicing defenders with a nice pass or turning a defender in and out? Obviously no, we need a striker that is comfortable of having the ball on his feet, somebody like Aguero to play next a mian striker that can run off the ball and confuse defenders, and catch them out of position.
Toni is expired, doesn't work as hard as he should. If you play him the long the balls, then you expect him to hold it and attract defenders, but he doesn't have anything left in the engine. He looks outclassed, outworked. and out of place out there. Matri doesn't convince me too.