An important consideration.
If you shoot IPSC or IDPA or train for gunfighting, you will find that you cannot depend on getting in a particular stance (def: "the way in which someone stands" (emphasis added.))
Your grasp of the gun should allow you to twist, turn, pivot, and lean as necessary to acquire the target(s). Setting your feet in a school stance takes time you may not have to spare.
Well put. I'm a modified Weaver guy, have been for 50+ years and it works for me. I'm comfortable in it, shoot well, can move and adjust to conditions. Mas Ayoob calls it the "interview position" in one of his articles...a good description.
Too, Front Sight, the NV based defensive shooting school, teaches the modified Weaver in their 4-day defensive handgun course. I've been twice, my wife once, and we found it easy to adapt to, their version of the classic Weaver.
While I don't participate in any of the handgun games where multiple targets are engaged, I do find that my version of the Weaver limits, to some extent, my ability to engage to the left (I'm right handed), without some foot movement. But then, my friend (nationally ranked in the Glock version of IDPA) demonstrated the isosceles to me, and moved his feet as well....guess it is what it is and you do what works.
Lastly, thinking on it, I find that about the only thing I do squared-off to another person, is shake hands....for any other human interaction, I naturally assume the "interview position" - "fighter's position", ie. the "Weaver Stance" to one extent or another. In a confrontation, it's what 71 years of living is going to condition me too, and it's where I'll find myself...and that's where my shooting "stance" comes from.
YMMV, Rod