The question was a speculative one. What could/should the Adders have done to set the stage for that alternate reality of events. And my response was me saying I'm honestly not sure.
I can't say that I see any reality in which the Adders call the other Clans players in an orchestra that they alone should be conducting and
aren't laughed at in response, but I think the only way for this stage to be set would've been for the Adders to have been out there putting their proverbial money where their mouth is when it comes to building Clan unity. Again, ironically and tragically, doing what the Spirits themselves once tried to do before giving up on the other Clans. And the problem is that the Adders have simply never been shown to operate in anything except their own self-interest.
WoK tells us that the Adders have long sought neutrality with the other Clans, but that their apolitical stance and alleged coddling of their civilians are why the other Clans look down on them. FMCC tells us that the Adders' perceived timidity (and what was Cassius' failure in his moment to speak up if not that?) and honorless methods of fighting are mocked not only by the other Crusader Clans, but even some of the Wardens. So I'd say at bare minimum, the Adders would have to do something about these perceptions first.
Now WoR tells us in Stanislov N'Buta's bio that he and his predecessors (of which Cassius was the most immediate) saw that the path to true power in the Homeworlds lay not in force of arms but in applying steady pressure as stalwart support, and we saw the Adders actually doing this in the Wars of Possession (when they got involved in the Cobra/Viper conflict on Homer, as well as their applying pressure in the Grand Council when they couldn't position who they wanted as ilKhan) and the Wars of Reaving as part of the Snake Alliance. But we never saw this sort of behavior before this point.
Personally, I think it makes perfect narrative sense that things unfolded the way that they did: the Adders were snubbed during REVIVAL because they were perceived (correctly so, IMO) as self-interested and timid, resolved they'd become the big fish in the small pond back home and bring about the downfall of the invading Clans because
they weren't handed the reins, got an unexpected stroke of luck with the Burrock Absorption, learned the art of putting the snake squeeze on their enemies by doing it to the Blood Spirits on York, finally started learning how to build political coalitions and apply political pressure during the post-Great Refusal Wars of Possession with the formation of the Snake Alliance, and then wielding that newfound political power with the same self-interest they've always shown by repeatedly cockblocking Grand Council votes they actually wanted to see happen because
they weren't being voted into power. Then when the Vipers did manage to take the ilKhanship with Adder support, they let the Vipers do all the heavy lifting of Reaving... and when they felt they had the opportunity to do so, they got rid of the Vipers as their biggest rivals
and the Spirits as their most hated enemies, finally securing the power they'd always wanted for themselves and holding onto it by applying pressure where needed.
One might even say that the Adders have the Homeworlds wrapped up in their coils, having achieved the Clan unity they claimed they always wanted to achieve by destroying or driving away all of their enemies and controlling the fates of those few Clans that remained by enforcing a policy of strict and violent isolation for going on decades now. If only those wrongheaded other Clans had just
listened to them, things would be different and the Inner Sphere would've been subjugated under their collective, combined toumans and the Star League would've finally been restored.
