Yeah, this is basically where I land too. Tromp has a nice “clean finisher with a story” quality to it: it’s not just another Craterhoof/Overrun, but it still gives creature decks a real way to stop durdling and end the game. The splashability is a real warning though — the first time a midrange pile randomly produces lethal from an otherwise stable board, people will remember it.
All Suns' Dawn feels much more like a build-around reward than a generic value card. I like it most if the cube already has self-mill, discard, evoke/adventure-style play patterns, or reasons to be base green 4–5c. If not, it risks being either narrow or just “draw three-ish” in the decks that can cast it.