Political Allies betrayal

[TheDog]

Testing the Sengoku Political Allies, all clans but mine are AI.

I was politically allied with the Hojo Clan, I just took back their capital and it returned to them as the original owners, as expected.

I was also allied with the Oda clan who then wiped out my ally the Hojo clan.
The Oda and Hojo were at war.

What is the best way to stop this happening?
<option name="alliancesCanChainTogether" value="true"/> ?

Are there any other options/variants?