Huddling Prior to a Free Throw

[Refhoop]

I have never gone looking for this, but it was an intra-squad scrimmage where the assistants were coaching and the head coach is in the background watching. I happen to be watching the officials work - near court side.
Free throw administering official said: break it up guys, which is what prompted the assistant coach to ask: "why can't they huddle?" Trail says to assistant: I'm about 90% sure they can't, but I'll check the rule for you... pretty lightheartedly. The head coach (in the background) blurts out: "well we're going to huddle anyway!". To which I thought; ok tough guy - Now I'll go look up the rule.
Generally, I agree with all of you; no problem... provided it doesn't become a competition for who can occupy the lane first for the huddle. Then two whistle blast and a strong "line em up!" should do it.
Just wanted some veteran input!