I think most baseball players lead their swing with their shoulders; allegedly golfers lead with their hips.
The most common coaching we get at fantasy camp is "Stay back". All of us, nearly, tend to "lunge" at the ball which means we leave most of our power (such as it is) in the box. The average pitching speed there is probably 60. Stay back stay back stay back NOW!!!
And I'd say "we" lead with our front leg more than shoulders, at least that is the first move made. That is one obvious difference with golf of course. I try and focus on keeping my back "closed" in baseball, stride forward still closed, and then open with everything in the swing. If that back side opens too early, well, you've lost any power. Of course, for most of us, the goal is to get it out of the infield and ahead of the OFers. A few guys can really hit pretty well, I've seen homeruns over the fence twice now, both by former college players now about 35.
The other commonality is to "keep your head down". it tends to fly open in baseball as well.
My pitching coach described the process as akin to a castwheel, you should kind of "spin" off the rubber, driving with your back leg, again not opening up too soon. It's interesting, to me, how prematurely opening up is such a problem for most of us. I hear major leaguers get into it at times as well, and of course on off speed pitches, many do it.
If anyone here has a bit of room, take a baseball out (by yourself) and see how far you can heave it (after loosening). So far as I know, the only way to "warm up" for throwing is ... to throw. I'm always amazed that major league pitchers warm up in the pen and their first pitch usually is 85+, you can heat the catcher's glove "snap", I used to love that sound. These guys have probably thrown a bit under the stands, and before the game of course, so they aren't dead cold.
I do think that golf is one game where you can fully appreciate just how far your skills are from a pro when by yourself. Maybe you try playing from the back tees on a municipal course and imagine the fairway as being a third as wide as it is and the rough being ... rough.
These guys are the elite of the elite of the elite. It used to be in fantasy camp that we'd play an inning against the former pros, it was pretty amazing to see these guys pick ground balls and pitching (their arms are mostly shot badly now). They got too old for it apparently and we don't any more. I recall "batting" off one of our coaches who was still young and I fouled a couple off and he told me later "Enough of this", and he went from BP+ speed to real speed. The ball sounded angry. I flailed away. Not a chance.