There's a "fundamental" (

) difference in that while Saddam was more of a realist himself many of the Islamic groups are ideologically pure and wouldn't be too willing to associate themselves with a regime they would consider apostate at best.
Moot point--seeing as how Islamic radical groups do in fact associate with "apostate" factions on a regular basis. No, it may not make sense to you, but the fact that it
does happen renders obsolete the question of whether it should.
Their excuse for associating with heretics is really pretty sensible: when you're forced to choose between two evils, you're going to get one or the other, and there's just nothing to be done about it. Generally you're going to choose the lesser one. If an Islamic radical nutcase faction sees the United States as their biggest problem, they'll readily swallow their pride and associate with, say, Basque separatists. They may not like it, but they'll do it.
Anyhow, the OP doesn't open up any new territory for me. What, exactly, does "no substantial contacts" mean? What if there's more evidence out there that hasn't been found yet? What if somebody reached the "no contacts" conclusion as a result of a mistake? What if the article quoted in the OP is a flat-out lie......?
All unanswered questions, but then I consider them secondary. Regardless of how you answer those, the fact remains that Saddam was a dictator, and that all by itself is sufficient justification to send in the tanks and kick his ass.