Implementing 32mm minis into a 25mm d&d game?

I’m running a d&d game with miniatures and battlemats at 25mm scale, but I also wanted to have some of my 32mm monster models from warhammer into the game. I was wondering if someone else has tried implementing this before; my current idea is to give them an “above average” size class, where they have the stage presence of a medium size class while their weapons are always treated as if they have the “reach” rule. But I’m unsure. Advice would be great! Thanks!!!