Coming from a different angle, I think this garments itself to much more versatility than you are giving it with those terms.
Legacy is so far being used as a token generator that can flying smash, but he fits many roles, a stall team can use him really well if they have a sniper, since he can cover and heal.
Dawn even more so, as she has her citizens and powers combined to create a great amount of role versatility.
In my prediction of where this game should be headed meta-wise, is your ban being your most important pick, using it to block the main counter for your options. After that you grab strong, multi-role heroes that allow your third pick to decide your team's strategy.
For example, Wraith, Unity is a fantastic opener, you can go all out champ-knives, you can go alone wolf with Wraith and frontal assault with swift & chomps, and your third pick will largely decide which approach you take, with more options for some choices. Add in Dawn for example, and you get a lot of support for either of those styles
Truth with unity and dawn while Wraith and Champ split off is wicked, while luminous plus bot rush is strong, or my favorite, stun bolts, BST, and a turret rush gets really creative.
I think the real strategy is going to be lining up powers in ways people haven't seen, and being able to counter while the other team can't get a good read on you.