Hidari, Senri Kita and Yusuke Kozaki are the big three for me.
It think Kita's work shines more with specific characters, the wider cast and some attires can look a bit plain (though suitable) compared to the others in the same game, generally the lead characters and Laguz tend to stand out to me a lot more, Ike is tops, look at that stern expression.
Kozaki's artstyle helped sell Awakening to a wider base, their art direction has always had a certain flair to it that makes it pop among anime styled humans, there's some interesting takes on the usual archetypes even if not everyone is gonna be so accommodating of the calvary toilet armour.
Hidari's work on echoes is like a perfect middle ground of the above for me, it just feels right to me and I'd hope they return if another echoes remake pops up down the line.
I do love that Heroes brings some of the old artists back in for content as well as a host of new ones, they don't all land but I appreciate the various takes on characters none the less