Wow. Those must be some cheats/mods. I don't use mods, but the highest I've gotten my own party before is probably somewhere in the 350 range. I don't think I've seen a companion over about 225-250, even Nathanos. For actual companions, not family members, I've never seen them over 200. I've never gotten any skill over about 270 before. It might also have to do with the settings I suppose. I use Easy settings, maybe Easiest would raise some of those things.
The above was a game I played for about 2350 days before getting frustrated and giving up on it. I got control of maybe 60% of the map. I admit I don't read all the forums figuring out the best ways of doing this or that, I prefer to figure things out on my own. I don't do smithing as I'm not here to play a crafter. So, yeah,I've never actually won a game despite playing over 1200 hours.
I'll also admit I enjoy Warband much more, having played that over 3000 hours. Thats a game I can win, this one I feel that with being unable to eliminate factions (other than being a homicidal maniac executing everyone), even for a short period, its too hard to avoid having factions attack you from all sides at once. Plus, my fellow lords are irritating. I watch them besiege something they can easily handle, I plan my own sieges to complement thiers, only to find that just before their siege should start, 5 minutes later, they decide to pull off of it to defend something half way across the map that they won't even be able to reach before cohesion forces them to break up. Or situations they've pulled off to hit a target thats become easier, when they could have finished their siege before going elsewhere. I want to end a war with good gains & they oppose me, but will accept peace later when we've lost those gains. They enjoy accepting wars where they've lost something but can't stand winning wars. We're already in a war and doing reasonably well and they want to start a war on the opposite end of our empire (where we have no troops) with a nation larger and stronger than ours.