O I thinks its guaranteed that Takeda will have a go sooner or later, as you say he's hemmed in by you and Imagawa. He's bound to go for one of you, hopefully it'll be Imagawa but theres always a chance he'll go for you. Best case scenario is both Hojo and Takeda go for Imagawa, worst case they both go for you. As for Imagawa i'm sure he'll have a few ninja roaming around, and if Hojo and Takeda end up face down in the grass i'm sure Imagawa wont mind letting his ninga practise on your generals and family line....