I'm not sure about raymond, but if you went with that then I think that top line is a bit small and L Brown who is huge happens to be too far down on the 3rd line, so in that scenario I'd be happier with,
Stutzle-LBrown-Raymond
Tkachuk-Norris-Batherson
Formenton-Pinto-Abramov
Paul-White-CBrown
That would be an excellent start, before inserting other draft picks/trade returns.
I understand your concern but skating (and not just speed), elusiveness, shiftiness are even more important traits than size in today's game.
Stutzle is already 6'0 and 187 lbs and only 18 y/o, he's probably not at his physical peak. He has german genes and what is more than size is tenacity/strenght. From what I have read/seen, he is not afraid to battle for the puck. You know the saying :
"It's not the size of the dog in the fight, it's the size of the fight in the dog"
Duclair is not a pushover, he's not the tallest (5'11) but 198 lbs and can hold his ground. Another guy who seems to have good genes (Caraïbeans have good genes too)
The 3rd guy on my line was Lucas Raymond (5'11 and 170 lbs). Yes he will need to bulk up but that's another guy with great intensity and who "isn't afraid to get his nose dirty". He looks to me like a guy that should mature into an Alfie body type.
But anyway, we'll have so many options, so maybe like you said a Brown with Duclair/Raymond could be a solution. And the good thing is we already have several guys who seem to be excellent to great athletes with size (Tkachuk, Batherson, Formenton, Norris...)
First we have to know who we'll draft. It could be Byfield instead of Stutzle to begin with. Then who would be the #5 OA pick? Too many question marks at this point, we don't even know which duos will work together (duos have been a trend in the NHL more than trios). The only one I could see being very likely is Tkachuk-Norris.