I was the one who made the connection, and I was the one who posited that adding JE to the trade might make it worth it to Cleveland to part with the 1/1. Here's what I was thinking.
1. JG is not enough for 1/1.
2. BB would only trade JG if it could bring back 1/1.
3. As sweeteners go, trading a WR who has had past success with JG would increase JG's value to Cleveland
4. JE's value to NE is diminishing. He's in the last year of his contract, he may be on the decline, and he is prone to injury due to his style of play.
5. BB does not mind sacrificing a star/key player nearing the end of his prime, even if it may seem a year early.
6. Trading JE saves the Pats about $4M which would be helpful if you have to sign 1/1
My thought about the Cassell/Vrabel trade was that Cassell was not super valuable, having already been inked at Franchise tag, and with a very questionable history pre-2008. Besides having been a very late 7th round pick, IIRC, there was some speculation late in the 2008 training camp that he would be cut as he had had a very lackluster preseason. Meanwhile, Pioli had just taken over a KC team in disarray. Adding an established and esteemed vet like Vrabel would be highly beneficial in that rebuilding process so he had value to the Chiefs. Again, as I recall, Pioli had been around to watch BB rebuild a Patriots team by signing vets who knew and bought into the culture he was trying to create. So in my opinion, Vrabel did add value to that trade and likely helped make the return what it was.