If I were going to get in shape for a boxing match and had the choice of either Drago’s carefully measured scientific workouts or Rocky’s outdoors “natural” exercise, which would get me in better shape for the fight?
*Yes yes, it’s just a movie. But it DID make me wanna work out, which not many movies do.
Rocky’s workout has the advantage of working out several muscle groups at a time, and being cheap. Drago can incrementally increase the intensity of his training in a way you can’t really do with “running up a snowy mountain.”
That having been said, there are a few implicit and explicit points to bring out of that montage:
Both those guys would have been training for weeks, if not months, in order to get into the proper shape to compete. Provide you maintain a level of intensity in your workout, I suspect either one is going to be decent.
Rocky is apparently too stupid to remember that he’s a mega-million dollar heavyweight champ, who probably has more money in his name than the Russian ministry of sport spends on Drago.
In several parts of the montage (correct me if I’m wrong, it has been a few years), isn’t Drago juicing it? THAT certainly helps you get in game shape. Of course, Sly is a hypocrite for making the big bad Russian a steroid monkey, given his unabashed love of HGH, but never mind that. 
Isn’t Rocky consciously eschewing the trappings of wealth? He’s going back to basics to force himself into the proper mindset for the bout; he thinks he’s gone soft in a way that technology cannot help.
Also, aren’t Rockys III & IV essentially the same movie, even more so than all of the series are alike?
I suppose this is true. But then to come back to the OP, is he getting that mental toughness at the cost of losing out on a better workout?
Both of the workouts they showed were pretty much symbolic for the purposes of the movie, more about Rocky getting back the “Eye of the Tiger” yet again. Drago’s “scientific” workouts were basically stuff like using a VersaClimber while somebody measured his heart rate and VO2, and Rocky’s “all natural” workout involved a lot of activity that could have been spent better elsewhere. Most boxing training is a mix of the modern and the traditional, and Rocky’s wood cabin logsplitting could be mirrored by Drago’s doing Tabatas with a sledgehammer and tractor tire in a gym. The whole scientific versus natural thing is mostly ficticious - the advantage goes to the boxer who works smarter and harder.
I don’t know if it’s “several,” but there is definitely a scene of Ivan “Death from Above” Drago being injected with something.
In these kinds of movies, the Russians have a ton of money and technology as good as, if not better than, our own. Look at Firefox or Hunt for Red October: The Soviets were rich, smart, and easily capable of fielding technology we hadn’t even developed yet.
This carried through into real life to some extent: The F-15 was developed in direct response to our misapprehension that the MiG-25 was an air superiority superfighter more maneuverable than anything we had, causing no end of shock when Belenko defected with one and we could get a closer look at the plane: It was an interceptor and, while rugged and certainly a good plane, wasn’t nearly as advanced as we’d thought.