All in all, viable but the issue you may run into is space - the Haromm group will find it pretty busy with all the tombs filling up the area up top and the Kardris tank will have a large and large add group to kite whilst also being targeted by the Toxic Storms and other things he'd usually avoid. If you swapped them round position wise, the Haromm group could faceroll it down south but the tank kiting up north would run out of space even faster.
Personally, I wouldn't use the strat if I had the option to do a more standard split (4/6 or 5/5), but I can't think of a reason that would stop you killing the boss using the strat you've suggested Good luck, let me know how it goes.
(PS: the slimes die in a couple of seconds and the DPS requirement for the boss is super low anyway, the final burn will wipe you if you aren't careful but the enrage itself is a non-event).
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