Really! I think they consider them as top 5-10. Middle of the top tier. Chinese, Mayans, Aztecs, Huns (thanks to buffing CA) and right after that Franks will come up imo.
At #2 with 55.29% win rate for 1650+ elo before DOTD. DOTD win rate didn’t come up with elo range yet but an FE dev said for 1600+ elo currently top 5 civs r Mayans, Franks, Indians, Huns and Teutons (not in order). So your opinion is wrong unless you narrow the elo range even more.
38% as ROF multiplies. TR doesn’t come immediately after reaching castle age. So your proposal will buff Ethiopians at early castle age. They have the highest win rate at <20 min among all the civ (considering all elo, for 1650+ it is Mayans) and their win rates fall with time. So if you want to nerf Ethiopians (and Mayans as well) mid game to early game is definitely not the way.