Well 0.72 Doesn't seem to have the problem at least not with my version. (tough that one might not be modified a bit.) I've played with the Semeucids this weekend and I4ve played a lot of battles where I played with 2 to 2.5 full stacks against 2-5 Egyptian army's (most of them were medium sized). Tough I'm not sure if there were any family members in the Ptolemy armies since every general I see gets killes within at least 3 turns. (I've got 3 assasins with at least 9 agent's skill and a few more. I wander what will happen if I've killed al the family members?)

anyway I've played so many battles with even more then 5 armies as reinforcements so I can't imagine that there are any problems in 0.72 or my version is modified so that the bug has gone away. (I've downloaded a few traits updates and other changes so that might explain?)