Ahh. OK. I see your reference point then. To be honest a few teams I have can solo heroic pit and I agree that speed is not a factor there. Not trying to brag, far from it, just more to point out that I'm talking more at the higher level of play. Arena, HAAT, TW, TB and Sith Raid speed becomes very important where you can have OK gear (not even maxed level 12 which is the 3 pieces), but if you have all great speed primary and secondaries you can beat out a maxed gear team with only mediocre speed mods.
Taking speed out of the equation, I would agree that mods otherwise aren't a deal maker. But that's kind of it. Mods are the only thing that provide major bumps in speed. So I kind of agree. Mods are not the factor. Speed is. If there was another way to bump speed in a big way we'd be talking about that instead of mods doing it.
As for your Pit team try Wedge Lead, CLS, Thrawn, Rex, and Raid Han. Rex will take care of any cleanse that may cause a hiccup in part 1 and of course thrawn can protect up and give TM as needed. Since I went that team I don't have to babysit at all. I used to use jyn but she wans't doing much for me.