I feel like with the Huns you should be playing domination and never founding a city other than the original anyway. Capture the cities you need.
This is the basic idea of how to play with the Huns. You do get into problems with your unit cap, science and gold but you really have to take advantage of and spam horse archers and get logistics with your horde and it makes you unstoppable if executed correctly.
If it's not over by turn 100 you're doing it wrong.
As for the rams, they are an odd UU, even though they make sense for the civ. In the game they have 2 movement which slows your advance and their cover promotions don't really make up for their low combat strength, and they usually end up dead. AFAIK they do not keep their +300% vs cities promotion either when upgrading to trebuchet. The time between them and trebuchets is really long and they can't stand any sort of heat after turn 50. Again, the 2 movement of the rams just slows you down. Having brought your HAs to your next target, you are waiting for the ram to arrive... it's a long wait.
So really the best thing to do is avoid rams and use horsemen as your city capture unit. This has the advantage of keeping the capture unit out of range of city bombard (can move after attacking without logistics), as well as ensuring the highest of speeds in getting the enemy defeated. So you will generally avoid the construction or philosophy and go for horseback riding first.
Alternative strategy is to play peaceful. If you have a bunch of pastures your production can look really nice, especially after stables. With god of the open sky pantheon, that's a ton of bonus culture too.