Actually the test is there for more than guarding against suppression. If that's all he was worried about he could get by with half that dose, maybe less. You could replace testosterone with a dose of 25-50mg/eod...some physicians who prescribe Test-P for TRT purposes actually give prescribe that dose only 2-3x per wk.
You're right, there's not a big difference in 6-8wks...I was just trying to keep it simple based on how he laid things out. He could probably run the Tren the entire 10wks he has set aside and be just fine, but if he were only going to use it for part of the cycle it just makes sense to use it once you're a little leaner. It doesn't make sense to diet with Tren then stop using Tren but then to keep dieting. The results from the Tren will simply be more pronounced once leaner. I don't know if I'm wording this right but hopefully so.