Allessandra shouldn't be compared to Forte really as he's not an out an out striker, when we've tried to play him as such it's been fairly obvious but when we've played to his strengths and played through him, ie. passing to his feet and letting him turn and create something for himself or a team mate he's looked good. If you expect him to do anything with a lofted ball to him or launching it for him to chase you're gonna have a bad time.
It's similar to Stead, despite him being tall he's actually a pretty useless target man, especailly compared to Ameobi who wins/controls just about everything you give him in the air, if you play the ball in to Stead's feet and don't use him as a target man you usually get much better results.
Allessandra is a fairly technical player, he has to be as he doesn't have the size or raw pace of some other players. Forte on the other hand does have some pace but is way less technically gifted. I think they both bring different things to the table therefore are useful options to have, unless we can find someone that has both sets of attributes combined there's not much point getting rid of Forte but I think he will go as he usually looks visibly miserable to me.