I think the concept of "pooling" unused hours makes the game more unrealistic.
If I understand correctly,
AC#1 is deployed to fly only between points A<->B as many times as it can, but has 2 hours unused, which we'll assume is less than an A<->B trip
AC#2 is deployed to fly only between points C<->D as many times as it can, but has 3 hours unused.
So you want to combine that to 5 hours of flight time that you can use on AC#3 which may fly P<->Q, just because AC#1,AC#2, and AC#3 are the same type?
That just makes it too easy!
I'm new to AE, and I respect some of the challenges that I've encountered:
I learned that if AC#2 flying only between C<->D has sufficient hours to take on an A<->B route, AC#2 CANNOT be added to an A<->B route since its only serviced airports on its flight schedule are C and D. I'd have to schedule a flight for AC#2 between C or D <-> A or B. To me, that's realistic and just another challenge in building routes and matching aircraft and configurations to pax demand.
I've also learned there is a BIG CHEAT build in, to dumb it down:
Right now "Daily Demand" is even: it isn't broken out by days of the week. So if a plane with 60 Biz Class seats is assigned 4 trips to a route that has a daily demand of 35 Biz Pax daily, all that demand is captured:
35 daily demand times 7 days = 245
4 trips with 60 seats = 240 seats divided by 7 days = 34 daily seats
Assuming a route with no competition, if I don't overprice, I'll get 100% load factor unless I overprice (or maybe other factors I haven't learned yet.)
In the real world, an airline that has 4 flights a week couldn't capture 105 of those pax, 35/day on the 3 days they don't fly.
Pooling unused hours means, for example three aircraft, one in Denver, one in Miami and one in Seattle, each with 2 hours, could miraculously fly a 6 hour route?
That would take all the fun out of planning efficient flights and city pairs.
Right now my airline has an overall utilization of 19.69 hours daily, and that's lower because I have two aircraft with about 8 hours available. My next airport expansion will take those into consideration.