First off, 100mg ED of tren?? Bro, have you run that dosage of tren before? For most people, that dosage would give you alot more sides than benefits... personally, I'd stick to 75mg at most.
Second, I'm not speaking with much certainty here, just thinking out loud... but by running the tren for the first 6 weeks, then again at the end of the cycle, despite the 6 week break in between, would the body still be "desensitized" (for lack of a better description) to the tren so that any results or benefits the second time around within that cycle would be minimal at best? I know there's been debate before about receptor desensitization or downgrade... anyhow, just food for thought.
In general, I think 18 weeks is a long time to be running that many compounds, even if you're running them intermittently. By keeping your cycles shorter, you still get great gains and you allow your body adequat rest and recovery. Just my humble opinion.