Cable gauge and ohm load

Regarding speaker cables, I’m looking for a little clarification on wire gauge and power requirements. I’ve read on numerous sites that for very inefficient speakers, you need lots of
power – that makes sense. In order to get that high power from the amplifier, you need
to minimize power loss. This means minimizing the resistance in the speaker cable. (I’m not addressing capacitance and inductance since while factors, my understanding is that they are not as critical in this application).

1. The shorter the wire, the less resistance.
2. The shorter the cable and the greater the cable cross-sectional area, the lower the resistance.
3. The lower the speaker’s impedance, the greater the importance of the speaker cable’s resistance.
4. The thicker the wire, the lower the resistance. (silver has a lower resistance than copper)

Given these generalities, how is it that super thin, small gauge wire such as Speltz and thin silver
cables are getting very positive reviews? Are these favorable reviews in regard to high efficiency
speakers?

What are the generally accepted guidelines for super low-efficiency speakers driven by
high-power amplifiers for:

a. Cable length
b. Cable gauge
c. Cable metallurgy

Would the requirements be different for bi-wired speakers where you could have separate cable runs for bass and mid/tweeter?

Your thoughts are appreciated.