Which IVs are better for Laslow?

I just got my last Laslow to finally make him +10. I can’t decide on if I should keep the current IVs (+atk -res) or merge my current laslow into the one I just got (+def -hp). I’m not sure if the 3 attack would be nessecarry for heavy blade to proc consistently or if the 3 hp for infantry pulse really matters since his hp will still be 55 and his C slot will probably change sooner or later.