Not quite. Think instead of spending a GCD throwing a glare/broil etc, a job had the option to spend that GCD dropping a buff on a player.
Obviously buffs would need to be rather specific to avoid ballooning out of control, being able to add a % to the targets damage would be an obviously bad idea, think more along the lines of a 'on the next attack the target does an additional xxx potency' style.
You'd effectively be dealing damage indirectly by way of your party members with an added bonus of making that healer's targeting a little simpler as they wouldn't be so reliant on switching between party and monster targets.
And yep, the En- effect was a big thing in FFXI, I assume that's where the inspiration for what we saw in the intro was from given that 1.0 was in many ways a sequel and reboot to 11.