I don't agree with the low SPM theories
This is perhaps the key point. In rowing we use all sorts of ratings (spm): 16-18 for paddle light to warm down, 22-24 for long distance work, 30-34 fast cruise in races, >38 for intervals, off the start and at the finish, up to 60 for backstop drills and warm-up. Similar on the erg, with the limitations due to inertia. Apart from paddle light and drills, all these are done at nearly full force and full length, controlling only the rating to control the CV load. We have three d.o.f, but effectively use one only, the rating, so the mechanical Work in each stroke does not vary much (say 20%) but the rating and hence the Power can double.
The aim of this protocol is to train the stroke itself. Rowing is the opposite of climbing Everest; there you'll need all sorts of techniques and methods and equipment and had better get them lined up before you start. On the erg or water, one is enough, the stroke; so what do we line up beforehand, if not that? Then once we have a full length stroke that will shift a boat fast, we use it. If you get a chance to listen to a 1x hull sing on flat water with no wind, you'll know why; some say it's the (second) best feeling.. We try to make this happen at low ratings over long distances, not thanks to some arcane rule or theory, but because it's impossible to do it at high rating.
To rate high but go slow (spin??) is fine on the bike, I shorten the gears and do it all the time. Afloat it can't happen, there are no gears; it would be fun to watch someone try though, especially a crew of novices.
PS. The videos posted here for criticism usually show disastrous style; the OP is no exception. Please don't suggest a style is acceptable when it's not, or suggest that by more training things will get better. They won't, worse is more likely, if not injury. If you've ever been to a regatta you'll have seen that crews with better style go faster. This is because good style is harder work than bad, so not only makes us go faster, but also trains us better. Need I quote Xeno? He says those without good technique begin to fall back after the first 500...
Rowing is not difficult, technically; relax, pull long hard and move in sequence and you're well on your way. But there's no percentage in thinking it's easier than it actually is.
08-1940, 179cm, 83kg.