Crisis Core would definitely have some advantages, being based off of a main franchise game as well as a larger install base, but there are some other factors to consider :
1) PSP's erratic software sales
2) How good each game is
3) How many fans were "burned" on the other FF7 spin-off games
4) The Wii is the "hot console" right now (and probably when these two are released), and any big games for it may grab more attention for it than other platforms games at the time
Nobody is crazy enough to accuse me of being sane.