In my Macedonian campaign I´ve tested this “trick”, as I tried to hold the front between Antiochia , Edessa and Seleukeia against the Seleucids. I occupied the Seleucid town of Arbella and sent a 5-star-diplomat to a Pontic city (my allies) in order to make Arbella a gift to Pontos. They dismissed my offer because they could not countervail this gift. The same happened when I offered Arbella to the K.H. (also my allies). Have you any proposal to impose Arbella to my allies?

Regards Marcel