Please check in HC what they thought Matt Ryan, Joe Flaco, Steve slaton, matt forte, chris johnson ect ect what they "thought" their max potential was...Is it anything close to what they did IRL. short answer no.
People dont know how a player will perform in real life its impossible to say that his guy wont be able to do this...This is the inherent flaw of the stat system. By setting a max stat catigory for a player you utterly nerf players that IRL could play well and in madden they might play well but wont ever get the attruibutes that say he is amazing because its all set in stone.