I imagine the ones that killerbee and I posted at the end of the previous page:
difficulty of balancing 3 xan attack fleets against each other (let alone others).
xan gains more out of having extra pod classes than the other races due to their extra effectiveness at fakes.
the wraith was a bit of a monster
the two cr with single target on cr and bs with one very low init and one pretty high seems very artificial and odd... there may be more reasons feel free to post them if you think of more