Isn't the 4 mobs it hit random (or effectively so; even if it's the 4 closest, good luck getting that to cycle through while running)?

If that's the case you're wasting your extraordinarily absurd luck by using it on a game.

Not how it works, you just have to dot the slower mobs first then get out of their range but in range of the faster mobs. It is skill not luck I assure you

It will always hit the same 4 mobs in zone, given that all are in range. IIRC its based on what order mobs spawned in zone.

Thinking of starting again was curious are bards popular or in demand or people ask for other classes...

I have had zero issues leveling solo or finding groups as a Bard. Some people hate on the hybrid penalty but if you play well their hate quickly turns to love.