What do the rest of your mid-slots look like? In L4s, my Machariel usually runs an XL Shield Booster, Boost Amplifier, 2 Hardeners and an Afterburner.
Personally, if I had to choose between a tracking computer or a web, I'd go with the tracking computer. Between that and your drones, frigs shouldn't be much of an issue.
I imagine that with your setup, you are affected by frigs more than me, thus you need to kill them faster (and you DO kill them faster). I probably kill them slower, but have more tank so they don't affect me as badly. It's really 6 of one, half dozen of another. Both work great, just comes down to playstyle.
But I'm rambling - keep the tracking computer.