It may work, you'll have to monitor the situation for a while though.
Similar situation with larger fronts:
A year ago I added some 3"-3.5" frontosa's into a tank that contained 10"-12" frontosa's and for about 10 days the larger one's seemed to exhibit behavior that was semi-territorial/semi-predatory toward the smaller one's before they accepted them (and no longer behaved like they contemplated eating them).