Help with Knight basing

Hey all recently started collecting knights, I have a dominus already and just bought a questoris. However I can not say I like their default posing. The dominus will keep his since he was built first a little while back when I was still new to the hobby and rather scared of modifying the models. But I have more experience now and so was wanting to change that.

Came up with the idea for him to be standing on a destroyed chaos vehicle of some type(original I know(though still debating on a rhino or traitor lemanruss)) and have run into the biggest issue of which prompted posting this.

The rhino is kinda large. I was doing some online mockups to test and see and uh... the rhino will over hang the base edge by a lot. Thats on top of taking up quite a bit of base room as is. The leman has the same problem. And this is after doing a decent amount of trimming down and making them looked wrecked.

Will that be fine? Or should I try and do something smaller? The models are set to there actual model sizes so. Any advice would great.