Well, I'm not really mad or anything but it is kinda annoying, especially now that it's becoming some kind of trend on the internet among gamers. I hear people saying it in games both in and out of context. What I find annoying I mean is the concept of RNGs in games, not you or what you said.
Personally I'm pissed off as a programming math/logic fan that programmers felt the need to even have RNGs exist. Theoretically every RNG should produce results roughly equal to the chance originally expressed without the RNG's intervention (10% should still feel like 10%). In which case, why even bother making an RNG?
The only thing RNGs do is guarantee a failure/success in some circumstances. For example, for a 10% chance to critically hit, if a guy actually hits 10 in a row the RNG can guarantee he won't hit the 11th no matter what you do. The thing is that a good RNG should not be noticeable to players at all (otherwise it's a bad RNG lol). Like I said, 10% should always and forever feel like 10% even with the RNG. If that's so then, why not just let the random numbers actually play out? A 10% chance to hit in a large sample size (like 10,000 attempts) will roughly show you a 10% turnout (maybe 936 or 1,092), even if there's a lot of consecutive hits in a row in there.
The reason it pisses me off is that if applied to a game like Warband, it implies that under some circumstances it would be impossible for certain things to happen that should be random. For example, when trying to recruit a lord to join your army, there is a certain random number that is calculated after all factors based on circumstances and your dialog choices are factored in. If you have a high enough relation with him, you say everything he wants to hear, your court and his current liege's court would hold him in roughly the same position and his family isn't in danger, you might have a 75% chance to hire him, which is a really high chance. If you fail due to the 25% chance, if you reload the save and do everything again you still have a 75% chance to hire him. An RNG that is designed to prevent you from being too successful beyond the projected success rate can prevent that especially if you've been getting too many successful lord hires recently. Because you successfully recruited 10 lords in a row recently, for example, the RNG will try to bring it back down to 75% and you're guaranteed to fail your next 3 recruitment attempts, no matter how good you are at smooth talking them.
Bringing it into context with this topic, if RNGs existed in Warband, it could mean that if the Vaegirs have been winning too much, the RNG could force them to suddenly suck. If your low level troops have been too accurate with their bows and getting too many kills, an RNG can force them to miss more shots just to make sure that they're weaker than higher level troops. And yes such RNGs exist in other games.