What counters Ethiopian archer + onagers? Is it cheese to use it in low elo?

So I got my buddies to get the game and we practiced and practiced and practiced against bots, and eventually, we started moving to play ranked 2v2's. I decided I'd play archer civs, because I found massing archers to be quite fun and I played with a mostly scout => xbow strategy. Trying all the options, I stopped at Ethiopians.

The thing is, after a 10 game win streak I feel like I'm cheesing the game. No opponent so far has had any chance to do anything against me. And what could they? The only thing I can think of is rushing to castle age and amassing 20+ knights before I have the time to make 50 xbows or mangonels. In imp, perhaps mass paladin spam? People have tried outnumbering me 3x with skrims but my micro is decent so 5 onagers with torsion engines immediately erase their army from existence. Another thing no opponents at this elo do is raiding the opponent's base - I swear I would've lost my composure at least half of those games if they sent like 3 knights to my base. I think the main thing is that people don't commit to counter-onagers enough. They make like 5, I kill them and then they give up completely.

On one hand, I feel kinda bad because I think mass archers are one of the most difficult strats to counter at low elo (I'm currently at around 1200), but on the other hand, I quite enjoy this strategy, so I'd like to know what areas I can work on to improve and be prepared to be countered with.