Hmm you must have a different codex from me I can not find any of these units in the IG.
You're either seriously not paying attention, or you're being deliberately obtuse in order to provoke a reaction. Either way, please knock it off.
He's not saying the BC isn't good against IG. In fact, he's AGREED that it is. All he's saying is "The BC is a good choice because it's good against IG" is not a good argument because you could make the same argument for the Klaw being good because it's good against the aforementioned types of armies.
If you're custom tailoring an anti-IG list, then fine. But if you want to make any OTHER kind of list, the Klaw is the better choice because it's useful against more types of units.
He's agreed that the BC is good against IG, you've agreed that the Klaw is good in a take all comers list. You both agree, so drop it.