Well, given how the last few threads went, this is probably going to comedown a decision of whom we like less, the princess or the changelings. They'd absolutely love information on what a seemingly weak strategist twilight is and her location to 'strategise' with her, no doubt they'd take her out if we showed real disdain for her, and it most most certainly put us in their good books. Hell, they'd probably drain enough from her and the still loyal guards to overpower the humans for a day... but would it be worth it?
Alternatively, we can convince them that working with the royal guard in the long term is a good plan, and perhaps someday it will earn them respect in pony society, enough to become regular members of it (kinda-sorta). We saw how downtrodden Tariff was, surely more must feel the same. After all, the enemy of my enemy is my friend, and ponies help their friends.
Or we can pop Whispens cherry and give them a feast on the house if things turn worse. Everybody's a sucker for free food.