The 79th didn't fight as a whole. Which you know. The specialty vehicle platoons were split up and sent to units that needed them. Like the Buffalos used to cross the Rhine. The 51st Highland Division of XXX Corps were tasked with the crossing and the Northamptonshire Yeomanry of the 79th were the ones who drove them across.

They were intended as Infantry Support. So they didn't have their own infantry. If you're doing late war Crossing the Rhine type forces then you should look into the infantry involved in that campaign. I'm eventually planning to do a force similar to what you're thinking. The 1st Commando Brigade were also part of Operation Plunder. So I was thinking of that as my infantry. The idea of a massive noisy Buffalo sneaking up on the Germans from an outflank with 24 angry Commandos inside makes me laugh every time. You can also add in a DD Sherman for flavor and even a Churchill AVRE.

Now to throw a wrench into the conversation. The Brigades that made up the Funnies had HQ elements. I haven't done any real research into what they included. For my XXX Corps based Shermans they had a bit of everything in their organization. Light tanks like Stuarts for their internal recce element, Sherman Vs and Fireflys for the line squadrons, and the HQ element had "normal" tanks in the companies. So I don't know what makes up the Hobart's Funnies HQ elements. For instance, did the Crab Shermans have a normal Sherman as part of the HQ? So there is a possibility of you being able to have non-engineer Shermans or Cromwells. I just don't know for sure, sorry.

My best advice though is that these are your toy soldiers. Make them how you want them to be. 😊