I'm a bit taken aback at the standing up of CSOR *and* a "Canadian Marine Corps" *and* maintaining the Airborne Regiment. If they're all being assumed as having three full-strength battalions, that's pretty iffy to me. I know there's the difference of not having had the decade of darkness here, but as it is, CSOR's only at battalion strength. Meanwhile, more realistically, you've got a couple more infantry regiments standing up.
I'd see either CSOR being at full strength with a battalion or two of marine-oriented infantry or a regiment of marine infantry, not both. Were you seeing both units being at battalion strength on their own?
When you're exploring expanding the role of the Rangers, please bear in mind where they're coming from. These guys are only currently authorized twelve days' pay per year. They're reservists with a serious wilderness skillset and minimal military training. Went on a winter survival course run by them once, had a blast, got to know some of them and an idea of how they fit in the big picture.
Their role is sovereignty patrol, search and rescue, and acting as guides and trainers. Drop a company off in the woods near a Ranger patrol and help 'em site themselves. Help them feed themselves off the land as best they can if necessary.
You can give these guys more funding, improving their ability to train during the year, increase the number of "Patrols" (a Ranger unit is referred to as a Patrol, as opposed to the verb), and increase the number of positions a Patrol can train and support.
You'd have an extremely hard time developing a conventional military unit out of Rangers. They're laid-back, they're unfamiliar with military protocol, and they're capable of butting heads with regular force guys who aren't familiar with them.
As to actually forming an arctic unit, what's your objective? To put together some sort of deployable, modern, Canadian answer to Sweden's medieval Finnish troops? A respectably-sized, largely native army reserve unit? A largely Inuit infantry battalion in the regular forces?
For the last one, outside of the language-imposed segregation of Valcartier, guys don't get chosen for their units on the basis of ethnicity. If a guy gets sent to the "army of the west" and the patricia's, there's a pretty good chance he can stay there if he wants. But there's plenty of Newfies and guys from Ontario there. If you're planning on having a regular force arctic/mountain specialist infantry battalion in the north, I'd say a better bet's probably to stick a battalion of your newly stood-up CSOR up there, with reservist detachments in Yellowknife, Whitehorse, and Iqaluit. Offer these reservists plenty of funding for exercises in cooperation with this battalion, and get the Rangers involved. Offer signing bonuses for component transfers to the reg force for qualified candidates (eg. after completion of trades training).
In ten years, your arctic battalion might have a seriously Inuit face to it. But I can't see it being that way building it from the ground up. Moreover, you're already stretching your cadre with all the other infantry units you're standing up.
If you're thinking of a reserve unit, you're going to be hurting. A reserve unit needs a cadre of middle and lower ranks to function effectively. You're going to have to station at least a platoon of reg force in whatever centers to get a useful unit in the places you're trying to recruit from, and it's going to take time to recruit and develop junior leaders in the new unit.
