This is basically what they tried a few months back when they massively upped the number of VIPs to try and reduce stacking. Odd that at the same time they didn't do what they've done with delivery and a mission that used to be for 2-10 you now take 120 cargo for less money! They could have upped the passenger numbers needed way back fairly easily. But they didn't.Just to pick up on this...
It'd be nice if FDev could take the opportunity to take a step back and rethink the way ALL this stuff works.
Right now it seems like we've just got 3 types of mission; cattle transport, annoying VIP transport and annoying VIP tours.
It'd be nice if there was, instead, a range of mission-types available with a range of different tiers (requiring the different cabins) as well.
The more I think about it, the more I like the idea of just making the cattle transport missions into "charters" with big volumes of people to fill up ships in one go.
You go to the passenger lounge and, instead of stacking"X refugees want to go to Y" missions together, it'd be "World's End Tours wants to hire your ship to transport 131 passengers to X for Cr40m".
If you accept, you've hired your ship to the company so you simply can't take any more missions until you complete that charter flight.
They could deliberately offer the charter missions in group sizes of around 20, 60 and 140 to suit the max capacity of the Dolphin, Orca and Beluga - paying, say, Cr10m, Cr20m and C40m respectively.
And if the configuration of your ship doesn't allow you to take biggest group, that's just tough cookies.
Because IMO Passengers sell units. Simple as that