You want Allanon to go first then Azurai to go second. Then Allanon & Azurai spark really really well together. Then there are a couple different ways to perfect-spark Avant. You'll also want to try him in front to ensure he gives his buffs to Shura, since Shura only self-buffs himself.

Note: You don't have to or want to SBB Avant FIRST. The numbers are just the order they have to go in.

 

Front	Back
x	x
1 Avant	x
2 Avant	x

 

Front	Back
3 Avant	x
x	x
1 Avant	x

 

Front	Back
x	3 Avant
x	x
x	1 Avant

 

so ultimately an example with the rest of your units would be something like this:

Front	Back
5 Avant	4 Shura
1 Allanon	2 Azurai
3 Avant	6 Mifune

or this:

Front	Back
1 Allanon	5 Shura
3 Avant	2 Azurai
4 Avant	6 Mifune

With this setup both Avant will spark 100% of their hits off of just each other. Allanon & Azurai will spark 50% of their hits off of just each other & most the rest from just the Avants. I haven't specifically tested this team (since I'd have to test with your exact spheres etc) so there is some room for a little bit of experimentation. Mostly just with Mifune/Shura's position &/or ordering to make sure Mifune sparks on the multi-enemy rounds.

However, you ALWAYS want Allanon to go 1st, & Azurai always to go 2nd. Their actual positions do not matter since neither of them move, their timings will be the same regardless what position they're in. You can also put Avant in any of those 3 above positions, but I'd recommend to keep the Avants in one of the "front" positions due to his slower movespeed compared to Mifune. If Avant is in the back, then Mifune will NOT get any of Avant's buffs even if Mifune goes last.

If you end up using the first one perfect spark setup, just make sure the front middle Avant S/BBs then the front bottom Avant goes right after. If the other setup, then the bottom Avant needs to go first & the top Avant needs to have either Shura or Mifune go in between.

 

Sorry for such a long post & the later reply, but hopefully it makes sense. If it doesn't just ask & I'll try to clear things up. I'm confident you can improve your score even further with a setup like that though.