To put that into laymans terms, an amp that can "almost" double it’s wattage for each halving of speaker impedance load is a good current deliverer.
Look at the specs.
EG:
50w -8ohms
100w-4ohms
200w-2ohms
For instance very sought after huge old massive Mark Levinson ML2 monoblocks don’t have many watts into 8ohms but they do
25w-8ohms
50w-4ohms
100w-2ohms
200w-1ohm.
https://c05d22d421713559ae3382d5a980815d4cf5ca6a.googledrive.com/host/0B_s-XMmdi448RDhFR2hhdXVQRWM/Mark-Levinson-ML-2-Mono-Power-Amplifiers-.html
Tubes and mosfet amps, don't do these sort of currents, that why they don't usually advertise it.
Cheers George