I'd argue that the 300lb bear is more dangerous but frankly neither are. I live in bear country NJ, we see them routinely and have had one try to get into the kitchen some years back.
I've had a number of NBEs(near bear experiences) and ran into several that were 500+ lbs at spitting distances. Someone on crutches can move faster than these things. They just sort of amble along and aren't really in a hurry.
From a quick little skim of the reading, sounds like your bears are not particularly fearful and/or have gotten used to encountering humans?
I went looking for land speed of black bears and wound up finding a cute website article written from a Grizzly Bear’s perspective titled “ASK A BEAR”. WHen asked how fast bears run, the grizzly bear answers:
“Sigh. It seems like there’s always some human who wants to figure out a secret way to best me on foot. Can’t you just be happy that you’re (sometimes) smarter than me and have access to modern plumbing? It’ll have to do, because there’s pretty much no chance you’ll ever be faster than me.
It’s well-known that I can reach speeds of up to 35 mph; some scientists think I can even go faster than that. What’s less known is that I also have incredible endurance: On multiple occasions, scientists in Yellowstone have clocked grizzlies running 25-28 mph over a distance of two miles, and according to observers, I wasn’t even breaking a sweat.” MORE AT LINK
https://www.backpacker.com/stories/ask-a-bear-how-fast-can-you-run
I later found an article saying black bear speed is 30mph.
You have no clue. A black bear can go from 0 to almost 30 mph in the time you blow snot out your nose. And they can do that through thickets,brush, trees, rocks, ravines, uphill and downhill where you would’t think a rabbit could go. In cover, you don’t see them running, you hear it, a huge crashing that diminishes quickly because of the distance and speed they cover.
The fact is they never really have to run because they are the bear and you are not. A big bear will usually only run because there is a bigger bear chasing it. Our out my way because we have hounds on it.
Don’t be telling fairy tales out of school.
The good part is, black bears can be killed pretty easily, when you have the shot.