Ok, so front rowers don't play as many minutes but their playing time will need to be equally managed due to the intensity of workload when on the field.
Using the same structure the Tahs probably need to manage their front rowers a bit better (albeit injury/suspension hasn't helped).
HJH (Harry Johnson-Holmes) is playing damn well but probably won't fall under Wallaby conditions (and would benefit from playing as much as possible probably).
Kepu and Fainga'a are the ones most in need of a rest it would seem, with Fitzpatrick and Rangi both Wallaby contenders but probably not likely to be forced to rest.
Other than Fainga'a, the Brumbies have rotated their props well although, again, injury has played a part.