I don't think Barca is a good fit for Mandzukic, he is very strong in the air but not the best technically and I don't see Barca changing their game and starting to cross the ball from flanks. But maybe they should consider changing game plan in the games where opposition parks the bus and standard tika taka football isn't enough to break them.
I believe Mandzukic is smart enough to know his line of play does not fit in with Barca strategy or else we'll see a replication of Barcelona been a bed of career-ending as some people you to say.
The player is still young though.