Advice/Suggestions needed.

So, with my pulls today (about 100 orbs) I got 4, 5 stars (2 LIke's, 1 BIke, and 1 Leif) and I got a bit of fodder (barely any greens) and I got a merge-able unit or two that I want advice on, namely, if using them with said IV's is worth it for the build I have in mind.

First is a +atk-hp sheena. My current sheena is -spd+hp I think, and she's merged up to +4. Should I merge them into the +atk sheena and make her do more damage or should I simply wait for a different set of IV"s
She runs Slaying Axe(def refine), Steady Breath, Wary Fighter, Bonfire.

Second unit is Boey. I've got a few copies (all with good IV's I might add) ranging from +spd-res to +atk-hp. This time however I got a +atk-res Boey, and since I want to use him as a owltome tank, I'm wondering which type of IV would be best for that type of boey (or if you recommend any other build with Boey per se (and he's gonna be 4 star merge, not 5 star merged)

Those are the two units I have in mind (other units are already setup). Thanks for the help/advice beforehand!