I did a bunch of personal wetsuit testing this summer and sim shorts tested better than my full sleeve suits, which I now believe is because they were too tight. (The shorts tested slower than my sleeveless and the full sleeve suit I subsequently bought). Anyhow, on the basis of this testing I swam Timberman in sim shorts and floaty calf guards … I believe it was my fastest HIM split, not by much if true, but it was definitely my best competitive result … course was perhaps a bit long or otherwise slow as times were not fast … so if you want to try I’d say go for it, especially if the water is near cut-off temps and overheating is a possibility.