I have to agree with ziging on his thoughts on siege weapon balance, indeed they are OP.
I also have to agree with him that spending build slots on fountains and statues is a terrible waste of slots. Because even though they are certainly useful, getting more resource buildings or economic buildings is certainly a better option by far. I think all factions should get additional statue/fountain-only slots in castles or otherwise this building option will never get used. You should of course make them expensive, slow to build, and require another building and an upgrade in that building to be constructed. Stoneworker would be the perfect building for this in Gondor, and given that that building generally is only built much later in the game, I see no problem with this suggestion.
On the resistance of rams against arrows, I hate to admit, but I have to agree with hoho96, Whale Sharku, and Sir Stig (boy, with have some weird nick names around here). See, I agree that, realistically, unprotected ram carriers should be slaughtered by archers. But ziging, I think you have to agree with me that the way arrow shooting works in this game, with all its precision, is almost as much unrealistic as arrow-resistant ram units. So yes, arrow vulnerable ram units would become useless, it doesn't matter if you put a thousand infantry soldiers around them, the player and the AI could just ignore the mass and make their archers focus on the rams and bang.
If you make ram units realistically vulnerable to arrows, then it would be only natural (not to say fair) to implement realistic unprecise archers that target an area instead of a game unit battalion and introduce friendly fire, and that would suck LOADS. But, as hoho96 stressed, this is not Total War (not that I'm agaisnt taking good elements from other games, I'm not), and the point of this game is not realistic warfare. It is a high fantasy game where you shouldn't worry logistics, ballistic and the fact that you just pumped a thousand soldiers from a small unproportional barrack in minutes. A barrack where you shouldn't be able to fit even one or two battalions inside, much less a whole army.