Re: Let's say you just got a JBJ and CCJ and you have a Les Paul...
If you like ultra smooth "woman tone" from the neck try JB in the bridge and CC in the neck.
(I'm still curious to try this combo myself)
You wont get standard neck humbucker tones with a hot bridge humbucker in the neck. If you are interested in exploring unusual possibilities, there are a bunch of options.
Stock pickups, I'd go JB in the bridge, hot wind with A5 magnet in the neck is going to have huge imbalance problems with an A2 magnet in the bridge. CC in neck may be too fat and butter, though.
Magnet swaps, there's all kinds of fun options. Either in neck with A3 sounds a lot like a fatter version of itself as an A2 magnet bridge pickup. The A3's extra high end helps keep it workable for fat cleans in spite of the emphasized lower frequencies from the neck position.
The Custom series are very popular for magnet swaps in this forum. Ceramic, you have the original SH-5 Custom. A2 is of course the Custom Custom that you have. A5 is the SH-14 Custom 5. With an A8, you get the popular forum "Custom 8", which is sort of like a ceramic Custom with high end rolled off more like the A2. A unique vintage open roar, with a modern punch in the low end. Then there's the assorted roughcast A5, unoriented A5, and roughcast unoriented A5 combinations, in descending output and brightness. Unoriented A5 is partway between A5 and A2 [which is always unoriented], and roughcast shaves off the high end a bit compared to a magnet that's been polished smooth.
Just between those two pickups you have an A2 and an A5 for magnet swapping.
Swap an A8 magnet into the CC, and with even a stock JB in the neck could be fun.
And if you need either tighter with more bite, I recommend swapping in 0.5" screws to tighten things up.
I use a JB with an A3 magnet and three 0.5" hex screws under the wound strings as my neck pickup [it's also turned so stud poles are toward the neck, and bass side screwed in with polepiece screws raised under lower strings, all of which gives it very fat midrange under high notes and decent definition for low], in a guitar where stock it was terrible as a bridge pickup. It's a lot of fun as a neck pickup, great for fat leads and chunky riffs. It's a bit fat for thrash, but not many thrash rhythm players like any neck pickup for rhythm, exactly because the neck position doesn't tend to be tight enough.