Outside of week 1-2 Savage clears and Ultimates, where you need to push every single % of damage to optimise your odds of clearing, not having 2melee 1 ranged 1 magic isn't a problem. I have seen 3 caster clears on P4S. 3 or 4 melees is a little iffy but some fights can be done with 0 downtime. 2 ranged (typically 1 caster 1 ranged) is used because PF spreads usually cater for this.

The 1% is fine. Some players will stick to the standard comp, but it doesn't mean you have to if you have the capability to.