If you have any of them I would honestly consider them before a 5*, for the titan scores and wars. Def- is better than atk+, and it’s even better when combined together.
Also with Evelyn, pretty much any offensive green hero is viable, at least in offense. That includes Elkanen.
I’d consider Kadilen and Margaret to be on par, kind of. Both aim to protect their teammates from special skills, Margaret’s is luck based though whereas Kadilen’s is consistent but doesn’t avoid other ailments like DoT.
Much like @DaveCozy said, I’d probably focus on some of the really valuable 4s too. You have 15 heroes maxed with some of the best 5s, but appear to be lacking options for colour stacking and war depth.
If I were you, I’d do Wilbur (!!), Grimm and Caedmon if you have him before next 5. Then maybe some healers, if you have them (Kiril? Rigard?). For 5, I’d consider Elk/Kadilen or Alice/Magni.