I think there's a topic on TGP asking when someone will design a HB able to sound like a real single-coil when split...
And beside something like a Stag Mag, there is not much choice (well, my Tele has a gorgeous underwound SC tone once its neck HB split, but this neck HB is a CuNiFe Wide Range, with rod magnets too).
Now, there are basic things to take in account and able to make the tone
more or less "fenderish" with humbuckers.
When I've a standard HB with the usual inductance (+/- 4H), I split it: it gives a 2H single coil.
When the HB involved is a hot one with a high inductance, I wire it in parallel. Again, it gives +/- 2H of final inductance if the HB is a JB, for instance.
Why these choices? Because a Fender single coil has often an inductance of at least 2H, not less (and rarely more than 3 or 3.5H, even with the hottest bridge Tele SC's. Well, granted, I've one clocking at 4H but it's an exception. So, in most situations, wiring in parallel a regular HB would make it too weak and splitting a hot HB would keep it too fat).
I remember a SH13 (!) sounding
deliciously fenderish once in parallel in a guitar with Tele specs (Fender scale, alder body, bolt on neck).
Many things can be done to fine tune the tone with any other pickup, by using no-load tone controls, adapted treble bleed networks, partial split recipes, parallel low value caps to warm up the sound, parallel inductors to brighten it... but here we enter in a territory requiring the use of some lab devices to check the results.
So and to keep it simple: Fender tone from conventional HB's= split, Fender sounds from hot HB's= parallel. Should give a decent result in
most cases.
FWIW (a rambling attempt to help).