output is not ohms. that is very true. but what the tech is talking about is that in gerenral (other factor apply) a pup with greater resistence has more windings and therefore likely more inductence and therefore likely more output.
there are humbuckers with high impedance and lower output and low impedence with great output.
the non issue that some people worry about is that the lower output pickup will short out the hot wound pickup making the mixed position sound alot like the low output pickup. non ballanced output isnt a big deal on some setups, the neck position can put out a lot of volume with a mild pickup, there are many guitars with a single coil neck and a "distortion" type humbucker bridge. you can balence it out in some cases without too much difference in height.
this is also a reason that mixing active and passive doesnt work to well, if you boost the lowwer pickup the output impedance of the boost circuit is subject to short the pasive pickup, you can match the output impedance or isolate with audio transformers but its usually not worth it, you can buffer both pickups seperately but most systems dont.
anytime two pickups are in parallel the inductance of the circuit drops, if the inductance is similar between the two you wind up with about half. this will give a higher resonant peak, this will emphisize some harmonics. if the inductance is very different the combined position will be only slightly lower than the lesser pickup, in this case there will be little difference in sound from neck to middle but a big difference from middle to bridge. (assuming the H is in the bridge)
the middle position will pickup some more harmonics over the neck only position but it wont shift the peak up to emphasize them as much. volume output and jumps will depend on a number of factors. Q, the magnets, the pickup heights.
can it work? yes! will you like it? depends! is it often more satisfying to have similar pickups all around? i think so but not always, volume jumps can serve a purpose, to push into slight overdrive on command comes to mind. the difference in tonality might be unsettling but it might also be exactly what you are looking for.
the multi volume setups are often less satisfying than you think, especially if the output is not balanced. some like to reverse the way the pots are wired to give better blending, this can give a noisy instrument at low volumes as well as a muddy sound at lowwer volumes and is why gibson didnt wire it that way. without the alternate(noisy) wireing dropping one volume drops both but at un even amounts. in this setup it is better to have ballanced pickups, the mixing effect is subtle and dual tones along with it can add slight texture to the sound otherwise not available. of coarse these are my preferences not rules of any kind.
dont be afraid of inbalance, magnets can be changed/spaced/whatever, but dont go overboard on a hot pup. overwound high inductance pups can get muddy sounding especially if you try to lower them or modify the magnets to achieve balance. it is easier to fatten up a pickup than to make it brighter, capacitors can work tonal wonders. a medium output humbucker like a paf is probably perfect but you may want to go slightly hotter or milder depending on taste.
