
Oh god, what are you doing?!? Why are you letting a culture based on RAIDING into our backyard? You were so worried about them breaking their deal in a couple of generations that you didn't want to set up a trade route to the mw, but now you want them as neighbors? What?!?
Worse, this will piss off our semi-allies! These are the human equivalent of locusts! They'll probably refrain from attacking us, but the WC and ST? Yeah, right! Do you remember how pissed we all were when we thought that maybe the ST had called the drought and caught us in the fallout? Well that's what we're doing here, and this would be absolutely our fault!
Stop! This is dumb and immoral!
First off, once we relocate them into the lowlands, they're honor bound to avoid raiding us for a few generations, which is plenty of time for us to build up our defenses along the borders.
Second, even if they were inclined to go on a raiding spree, do you really think the nomad's first target of choice is going to be the friendly people who live in fortified settlements tucked into forested and hilly terrain?
Thirdly, at this point, do you really think we care about our neighbors opinions? We have:
1) Dead Priests - everyone hates them for being super expansionist asshole cannibals, so they can just fuck off
2) Spirit Talkers - another bunch of assholes who're eyeing the lowlands themselves and tend to screw us over every time we interact with each other
3) Western Confederation - on the verge of collapse. A lot of their people have fled to our lands to escape the drought and DPs, so it's only a matter of time before they're defeated
See, the nice thing about this situation is that no matter what happens we stand to benefit.
Nomads and DPs are stuck in a long, painful stalemate? More time for us to do our own thing at home. Also lets us collect more WC refugees to boost our economy.
DPs crush the nomads and WC? The nomads and WC still buy us time and bleed the DPs heavily before they even reach our borders. We also nab the fleeing refugees, boosting our economy and giving us a turn or two to go full military expansion before the DPs arrive.
WC and nomads somehow crush the DPs? Now they're fighting the STs for control of the lowlands, leaving us untouched and letting us absorb all those poor DP refugees.
The only way that we can lose is if ALL the groups decide to team up and attack us for some reason.
Which... isn't going to happen. The DPs are too hated, the STs are too untrustworthy, the WC too weak and the nomads too politically unstable to maintain the kind of long term alliance needed to crack our defenses and destroy us.