You forgot one little but important thing: Zihark's affinity
With having earth he can have +22% more evasion than Edward can have at max. That's what makes Zihark a much better frontunit than Edward. His low luck and lower defense don't matter at all when he has the support.
Tbf Idk how good resolve + earth support is useful for Edward because I don't like to give earth unit a support which doesn't increase the evasion.
If you compare Zihark with Lucia because of their same affinity, then you're right. Otherwsie big no. Sure they have similarities in their growthrates (res > def) but Lucia starts 11 levels higher with only slightly better bases than him. Furthermore her growthrates suck. And her biggest issue is her terrible availibility. She's the only myrmidon / swordmaster who's really not worth for the endgame.
Edward is similar to Mia growthwise, but still, Mia doesn't need any effort and babying to get the levels unlike Edward.
Same goes to everyone in HM in part 1 whose name is not Sothe and Volug excluding the "guest" characters.
Even Nolan has problems to take two steel axes.