Tiaral

Their clan leader was slightly stronger than the ordinary guards of a "weaker" clan.

This is easily explained. When you go one-on-one after school, with knives, on Dust II, two of you, but without ultimates, and you, having spent two days on specialized leveling and honing your build for a one-shot kill, immediately use your ultimate before your opponent even has time to react, it's not surprising that you win.

And ordinary warriors folded very easily, even under our complete encirclement, without archers, and with the inability to use all melee fighters.

But I disagree here. As far as I remember, they were lousy archers, and they also couldn't use their own melee fighters, and again, half of them died from the alpha strike, but even so, they managed to get five kills, or even more. If we had clashed clan against clan, I think they would have given us a hard time. And a guy with lower combat ability should have an even weaker army and be weaker himself, with worse equipment. Unless he separately hired some mercenaries for his protection.