Zealots in terms of ideology but with practical execution, I'd say.
The dealings with the Horses are a good example of both: they were prepared to compromise enough to work with the Horses to crush the Burrock force, but they kept the Horses, now an IS Clan, very much at arm's length. The Adder Warriors who participated were considered Tainted even by that trivial contact with the IS (as in literally just setting foot on a single planet, lol) and they were basically cast out of the Clan to be absorbed by the Horses.
In terms of the WoR as a whole, the Adders were opportunistic in the years leading up to it. As part of the Snake Alliance they went all in on the Ravens to grab weakly defended enclaves but sat the Shark campaign out because the Sharks were pretty strong. As a result they had a mostly fresh touman and large amount of territory when everything turned to chaos in 3072. Being strong and having proper leadership (unlike say the Mandrills or the left behind Hellion and Horse garrisons) meant the Adders were in the best position to weather the storm out of all the Clans. Nobody really came out of the Wars or Reaving ahead, they all took huge casualties and had whole planets depopulated, but the Adders did the least badly of the surviving Homeworld Clans by a long way.
