I would consider replacing some of the plugs if needed. Home Assistant is powerful but way less user friendly than SmartThings and usually requires more tinkering. You can have both co-existing though, I imagine that would be a setup of some power users to expand automation options while enjoying SmartThings user interface.
There’s an edge driver for TP-Link devices but it may not work since it’s few years old and TP-Link changed the authentication scheme, guess it’s worth confirming it doesn’t before taking actions.