One trouble with too-few airframes is we work them like rented mules.
This is not a huge issue outside wartime. Especially with strat airlift. The CAF can and does use contracted air and sea lift as necessary. The CAF is also getting 9 tanker transports now. That is a doubling of the current Airbus fleet and with each aircraft significantly larger than the ones being replaced. So by 2030, the CAF will have more life than it's ever had.
The big problems with a small fleet are:
1) Little to no redundancy. Of 5 aircraft, at any given time, about 3 are likely to be available. Takes a minimum of two to sustain an air bridge to Europe. Say the fuel truck driver forgets to put the parking brake and dings the side of the aircraft. You're now down an aircraft for days to weeks. You may not have the lift to sustain your airbridge.
2) Leaves no room for attrition. Air force flying is risky. Sometimes we crash airplanes. When the production line is closed, any loss of aircraft is irreplaceable. This was actually a consideration for why we purchased the F-35.
3) Low density high demand. Strategic airlift isn't used much, all year round. But when the proverbial excrement hits the circulating air distribution device, everybody and their mother wants a ride. Canada discovered this during the Indian Ocean tsunami when our disaster team had a tough time getting a ride to Sri Lanka.
Small militaries like ours or Finland's can't hope to be all singing-all dancing these days, but the one concern I have with capabilities like strategic lift is some people who feel this and such areas as logistics should be our specialty at the expense of reduced combat arms.
It's a risk. But Canada is also unusual for a population of our size. We have an absolute massive country. And we're very high wealth. This means that Canada has the means and the necessity to field expensive assets (like strategic airlift) which the Finns cannot and do not need.
Interesting that you should mention engineers west of the Rockies in case of a natural disaster. Wasn't the engineering school at Chilliwack until they closed the base, leaving no regular land forces on the west coast?
Yes. But we've got lots of provinces with no regular land forces. This is not normally an issue. It only becomes an issue if you don't have the lift to move in an emergency.