Advice for an injured first time swimrunner

I've signed up to do a short swimrun with my partner, approx. 10k running and 2k swimming. I am a an experienced fell and mountain runner, so I'm not too worried about the run aspect alone, I also do quite a bit of swimming and open water swimming, but I am worried about the swimming with running gear; specifically I badly injured my rotator cuff a few years back in a climbing accident and can only swim breast stroke without risk, so paddles and pull bouys are pretty much off the table for me. If I'm not concerned about transition times,.how feasible is it to attach my shoes to a tow float for the swims, so I don't have to drag them on my feet- does anybody have experience with this please?