The problem of VATSing near groups of fast enemies is that each attack takes some time. For example for each VATS punch you throw, enemies advance a few steps. Which means you will get killed FAST. The only way so far I found (without taking a truckload of chems each battle) is to run sideways or backwards (depending on the enemy) attacking constantly, but there are certain enemies (feral ghouls) that have a "charge" attack that WILL hit you EVEN if you are running backwards with light armor AND travel light perk. It does around 50 points of damage so if you meet 4-5 reavers at once (like at Old Nuclear Test site), they will kill you again and again I used everything I could there, except chems, since I wanted to prove to myself it's doable without them. pushy, ballistic fist, Oh Baby, chainsaw, cattle prod... none of those worked. They just rush you running 200 km/h and do those charge moves that take half of your life. I have sincerely no clue how to deal with them with a melee weapon except stealth boy and sneak hit criticals or chemming myself up. I got tired eventually and blow their heads with a sniper rifle one after another. Was like a walk in the park.