Take a look at the "% Chance to Hit" calculator
http://uo.stratics.com/content/arms-armor/combat.php
The difference between not having HCI and having HCI is a 34% chance to hit vs a 50% chance to hit.
Also keep in mind that you have to re toggle your combat special move after every spell you cast.
If your targets are players that don't have high DCI adding HCI into the suit will get you to a 72% chance to hit, if they have no fighting skill what so ever you'll have a 100% chance to hit.
I think it really depends on the style of mage you play. If you are an in your face mage (close range to dexers for spells that are distance based like harm and poison) then it might work. If you run an Explosion/Flame Strike mage the usefulness of wrestling vs med/focus goes way down (note if you are a "focused mage" you don't want to go over something like 40). However being able to hit a stun on the run can give you that extra second to wall off a section and make an escape or make a kill.
I personally don't use wrestling and go for the 120 evaluate intelligence/100 anatomy for the 20 skill points.