I've been looking at videos of different Machine Athena clears (mostly for an idea on how to deal with annoying spawns) and I've seen a variety of team comps where the lead swap player lacks Rag Drag. In these instances there's two enhances employed. Fortunately Machine Athena provides the enhance, so it's really about getting a strong board. The Drake-->Aus-->Ath board is used for high HP floors by the lead swap team when needed which seems to just be Beelz. In these cases it looks like that team CANNOT be the one to take down Kali.
Thoth into Kagu is probably the worst spawn set this composition can face since you can't really stall since skyfall luck will basically hose your actives either way. You'd have to get pretty unlucky but it's still very possible. Thoth into Parvati's not so bad though since it's basically free stalling. The thing you really miss without Rag Drag is solid but not too much damage from dark combos. If Thoth comes up pray the player with the delay for Kagu doesn't get boned. Everything else is manageable.
Re: Super Krishna
I'd go for him since he'll be more available and you can do DC runs. That's not to say I wouldn't want a consistent Mathena partner but realistically there's a bit of work spinning the team up. Just farming MP for Rags was brutal. But hey I have a max skilled everything from rogues now. I'll probably never run Volsung, Gainaut, or Myr again.
Also reminder: Today is Star Den day. Anyone in group B, C, D want a partner to run with all hour let me know. I can button through as long as my partner has 9 SB and a red row lead (Yamato, Goemon, ACC).
I'm sitting on 452k mp (after buying Yomidra and You Yu previously). I could buy Ragnarok Dragon right now but he probably wouldn't be used much outside this M Athena team and GungHo may release stronger mp cards later that I would like to buy.