Low launch shafts and distance

Bare with me as a lot of this is just a brainstorm, but there is definitely a question in here somewhere.

I watch the pros consistently drive the ball with 280+ carry and they hit their balls way up in the air.  Now if you gave them a really low launch shaft what would happen?  I would think they would get less carry and more roll.  Or (if all else was constant), would they carry the ball the same distance?  I had a discussion the other day with someone who said the guy who hits the ball 280 carry and 5y of roll is always stronger than the guy who hits it 250 carry with 35y of roll.  I think that's wrong...just think about a baseball player hitting a line drive vs. a home run, yet almost always those balls are coming off of their bats around 100mph when they make solid contact.  Correct me if I'm wrong.

The other thing is that I've hit low ball flight and high ball flight shafts with the same launch angles but completely different ball flights, is that even possible?  I don't understand what force is at work here to make one go higher than the other, if all else is constant.  I would think the LA would have to be lower on the low launch shaft, but I've seen it on a ball flight monitor be exactly the same between wildly different shafts (maybe the LM was broken, I don't know).

So what's going on here, are the launch angles actually different between two completely shafts (and I'm just crazy), or does a low launch shaft perform exactly the same as a high launch shaft (in a vacuum, with all other factors constant) in terms of distance?  And if they do, then why is the low launch shaft actually decreasing the ball flight if it's not changing the launch angle or speed of the ball?

Though a low ball flight is sexy, and can give you a high max distance on certain holes, it's best to maximize carry or at least go a bit more for carry than total. But that still often means going for lower launching equipment for better players.

As for the shaft, it really won't make a drastic difference most of the time. It will affect the feel and accuracy more than the overall flight in the hands of a pro, since they won't be using a poorly fitting shaft. They won't go from bombs to line drives just by changing shafts, they'd need a loft and technique adjustment. I have a low launch shaft and a low loft head and I still can hit it for close to maximum carry because of how well it fits me. I do get more height on my shots from a softer shaft but the spin and launch angle can start to lose distance in terms of both carry and roll. Plus I know that if I hit a harder shot it will carry even farther while throttling back a bit, such as into the wind, will sometimes get me a bit of extra roll to compensate for less power. I also find that where I hit the ball on the face matters a lot; the middle is good but I can carry it farther if I hit a shot from higher on the face. Thin hits will glide like a wheelbarrow no matter what sort of driver you use.

A proper fitting shaft will often give more carry and more roll. On most courses I'd go with carry because of how awesome it is to carry bunkers and doglegs and stuff. It might be awesome to hit a 340 yarder on a downhill hole but not if you're only carrying 260 and can't eliminate hazards everywhere else. Once you get into PGA tour level swing speeds, it's quite hard to go too low on spin but often times their launch angles will be too low. The ones that nail both will usually get both more carry and roll than others at the same speed.