In essence it's a great idea...
The trouble is with DCS's one great failing - you cannot occupy an AI slot in multiplayer, only a dedicated client. This restricts the abilty to drop into a well balanced scenario and take the place of an AI - you end up augmenting an AI force and sghifting the scales of the scenario.
And with so many people wanting - or only able - to fly a single platform, each mission has to cater for a wide range of capabilities; some mission sets might only be realistically achievable with 4th gen platforms if there's only 2 or 3 of you on. Try the same in a 3rd gen airframe and you might find yourselves repeatedly shot down, unless there's more of you to saturate the defences.
It's a bit of a knotty problem that a well designed sandbox mission should get around by providing a range of targets of varying intensity of defence - there's a bit of something for everyone. Plus, if you want to do some coordinated action then usually there's some more heavily defended areas that do require a coordinated effort to attack - it's just that no-one seems to take the bull by the horns and actually suggest it!
However, I'd be up for some DangerDogz on tour adventures imnto some other servers to see what they're like...