M Grima +atk -def +1 or M Grima neutral +3

So I got another Grima somehow, and he's got pretty good ivs. However, I already have a +2 neutral Grima and I think that previous merges won't matter when merging later. So should I add this Grima onto the neutral one for +3 or merge the neutral one into the +atk -def one for +1