I have sat through a lot of physics and biology classes my time, and I am not buying what you are selling. Mass always creates inertia, and muscle mass may or may not produce enough force to counteract it. In most cases, in hockey, it doesn't, which is why the Connors and Ehlers of the world are so quick and lithe.
Big men--Finnish or otherwise, have a lot of mass to move, and there are many different ways to improve their efficiency in acceleration. The first is to limit the additional unnecessary mass gained, which is a real risk for Laine. There is no reason to believe that a 10kg weight gain through intensive weight training will equate to better acceleration and quite the opposite can be the case--just ask Morrissey.
OTOH, almost everything improves with practice, including skating drills designed specifically to improve quickness and agility. To eliminate this from a training regimen seems silly.
Simple physics: for great acceleration you need a great amount of explosive power, which is impossible to achieve without having enough of the fast twitched muscle cells. Some people are born with more of them and some with less of them. Tall and bigger sized people are usually born with clearly less of the fast twitched muscle cells than shorter or average tall people. A person whom does not have enough of those fast twitch muscle cells will never ever become good with acceleration unless he manages to add a good amount of that kind of muscle cells with training for getting the much needed explosive power. No kind of technical training will help you with developing your acceleration much at all if you dont get that issue fixed - it’s simply a physical impossibility. Speed comes through force and energy, and muscles are the organs that create them for the human body. Speed and acceleration doesn't come out of nothing or just through skills without the power, like some people here seem to believe.
Of course a hockey player should not have extra mass in areas which are not useful for his game. But Laine has been needing especially more power from muscles for both his core and his legs, to become exactly a skater with better clearly better acceleration. Just go and educate yourself by reading how Olympic speed skaters train. They do huge amounts of strength training for both, to their legs and to their core. If you don't have those areas strong and the legs strong with especially the fast twitch muscles, your skating will be weak and without the much needed power for fast acceleration.
Laine has had those areas weaker before. His arms have been always relatively strong for his age, but his legs and core were pretty weak before last off season, and he still has a lot of strength work to do with those areas, especially with his legs. Otherwise he will not develop his acceleration in the future practically at all. For sure he does not need to make his arms much stronger, so most probably he will not be doing that much strength training with his arms and hands. Some of course, but not with big amounts. He wasn't anyway doing that much of arm focused training for quite a while already.
Still, Laine’s biggest weakness is his lack of stamina for handling his big body. That has been extremely well visible, if you understand at all how it works for young athletes and their lack of stamina while still in the growing and strengthening process. So he will need to use a lot of his training time for training both, the explosive strength for his legs and his stamina. This means that he is training two things that are in fact even a bit contradictory with each other, so the time needed for effective training is really a great amount. At the same time the absolute truth is that he is a pretty good skater technically, so he just can’t be wasting his valuable training time at the moment for an area that seriously does not need fixing in his case. He has such bigger problems with his legs and stamina that some slight polishing through technical skating training would be seriously using his limited training time very unefficiently at the moment.
And remember, he is comparable with his training needs only to really bigger sized players whom have had similarly weak legs and leg injury recovering history during a similar three year time span. Comparing his needs for skating improvement with some under 6’4 tall guys with some nice luck with injuries is simply comparing two completely different situations with completely different kind of training needs.
I’m not trying to sell anything here. Just trying to educate here some people whom don't seriously seem to know what are the physical basics for having any possibilities to have fast acceleration. Unfortunately it seems that ignorance is bliss applies for some people here.
