That's where technical measurements can be useful: measuring the LRC specs and Gauss/Tesla flux then inducing the resonant peak(s) and impulse response of a pickup already gives many infos, opening to some educated guess. Sadly, it requires lab gear that most people haven't at disposal.
And it never gives the full picture anyway because of external factors : pots resistance, cable capacitance and pickups height interact with the acoustic resonance of each instrument in a way able to alter radically the voicing of a transducer...
That being said and to answer to the question with a concrete example : a SSL1 is "equivalent" to the mid pickup of the L Series Strat that I've periodically here in maintenance. It has not the same DCR (6.5k vs 6k for the "real thing") but it exhibits the same inductance (2.6H) and an almost identical resonant peak. Now, its rod magnets have also a stronger magnetism, hence a difference in tone...
Conversely and IME, a DiMarzio 36th b has higher DCR and inductance than a Duncan 59b, along with a weaker magnetism and a
noticeably different coils coupling... but I totally see how one could make them sound "equivalent" to each other by external means and why they can give the same overall impression.
To end on something possibly useful: the Atlantic Audio pickups database accessible below appears to me as an handy tool. If one ticks one or several of the boxes responding to a lenght and capacitance of cable typically used (rather than one of the Zerocap cable settings, useless for most players), it gives a rather realistic idea of induced resonant peaks for the models listed. It doesn't reveal anything about magnetism and ASDR envelopes but it's better than nothing and tells someting about the typical EQing curve of such or such transducer...
http://zerocapcable.com/?page_id=400
The list below is also interesting. It has been published by a self-taught "specialist" that I sadly find extremely dogmatic in his approach (with a clear tendency to deny what he doesn't grasp or has experimented himself) but he has done a great work when it comes to measurements, that I find on par with my own private data in most cases. And he has generously left the whole at disposal online so it doesn't harm to share the link:
http://echoesofmars.com/pickup_data...raphs~(~)~filters~(~)~filters_not~(~)~filter~')
FWIW. HTH.