What to do with extra Duma?

AR Defense for meme scoring during anima season.

One normal Duma, and merge the others into one big Duma? That way you have two dedicated for AR. Hopefully the experts will tell you if this math is good.

So if you have 4, go with a normal, and a +3.

I think he's a decent unit to have for AR def. Keep bold fighter on him or maybe if you use +atk, you could use wary + death blow or something like that, but basically his job is to make it hard for people to rush your setup. He doesn't go down easily himself, and anyone who wants to galeforce your setup will have to get rid of him or else he'll just kill any galeforcers that sit around at the end of their turn.

Also, extra atk is definitely helpful.

But you're probably going to want to fodder the bold fighter. Don't merge them all. You'll get enough kills on AR defense to save you a lot more lift than the tiny 1-2 lift per battle that you would save from the merges.