MikeATC Retired FAA, NATCA Member Nashville TN

NU,
If the GCA didn't have arrivals spaced 3 miles apart (which is the min) you could point out the heavy to the pattern traffic and say maintain visual seperation, caution wake turbelence from Heavy C5, Rwy xx ceared touch and go.

In all honesty, if possible when I have heavy traffic on one runway, I try to put my small traffic on another runway to greatly reduce the wake turbelence problems. I know that isn't always possible, so sometimes you'll just have to spin them on the downwind to fit the pattern traffic into the arrival sequence, or ask approach/GCA to give you room for your pattern traffic.