Just some random general thoughts on rereading this thread...
I don't understand some of the "one trip" reasoning. I'm trying to remember the last time I actually had to manhandle (is that word still allowed in 2018?

) gear any distance from vehicle to venue stage. Ah, yes, it was 3-1/2 years ago, and I brought a 1 cu. ft. Studio 110 and a bass bag on my back, because no cars allowed - downtown was closed for the Prescott Rodeo. Luckily the venue had FOH, but also a lot of stairs - a relative rarity out here. I pack a lot of gear on a cart if necessary and that's my one trip. No need for stuff I can walk a mile with as long as my cart wheels are big and round to make it through the tall grass and gravel, and over curbs without spilling stuff. ADA ramps help a lot too.
Not every venue has FOH support or house backlines. Maybe they do in the Big City, but not out here in flyover country. We even have elevators in the bigger venues where needed, mostly. So assuming tiny rigs for that reason depends on location. Sometimes you actually have to carry the room. Or the park. Sometimes you have the reimagination of young Jimmy Page on guitar, to boot. Or worse, a guitarist with massive hearing loss, to whom any sane SPL is inaudible. Earplugs mandatory in that case.
It's much closer to reality to bet that a 300W thermal-rated driver will start to break up around 150W, not 75, unless they're ancient, er, vintage, or use those cheapass drivers (no brand names mentioned), or are in a terribly mistuned cabinet. Your ears, if cleaned regularly, will tell you when enough is enough, and you need more cones.
Some players actually
are broke enough - BTDT - that they have to make do with gear on hand that they can afford, until one band or another makes them a little extra money. Not many of us are MacGyver enough to be able to assemble a bitchin' science fair project rig out of some phone wire and a couple of toy train transformers. Thus the oft maligned, much abused, cockroach-outlasting Peavey rig, or whatever good deal (maybe even a TC) gets ya to the next gig. Maybe even something with (shudder) mismatched drivers.
Just MO, YMMV, usual disclaimers apply, void where prohibited.