Less is more when you actually start vetting accessories.

All that is needed on a fighting carbine:

A1) The most durable fixed sights available (like the LMT SOPMOD fixed rear)

Or

A2) The most durable / kiss low power (or variable) optic (like an ACOG or Nightforce 1-4) combined with the most durable fold down front and rear BUIS (like Troy Battlesights). NOTE: front food down is manditory with low power optics - you will see a fixed front sight thru your scope and this is a big detriment to getting fast)

B) The best white light you can buy (like Surefire Scout)

C) The best two point sling you can buy (like Vickers)

That's it.

My wife likes a VFG because it helps offset her limited upper body strength. I like them as a hand stop (indexes weak hand in same place without thinking about it) and as a control / retention assist. They are not, however, mandatory.