Sticks or no sticks, I opt for an underhook.
I have participated in numerous full contact stick fights. I wear hockey gloves and a Bauer hockey helmet with face cage. No need for full body armor.
Fact of the matter is, people like to Clinch soon after the first hit lands. As Top Dog says, "Grappling happens". I'll take an Underhook over most other things as it allows me the most control over their movements. It also allows me to set up the takedowns I do with a stick.
Lots of guy's that I have fought use an overhook to go for the infamous "fang" choke. I have found a good counter for that is the Suplex. Secure your body lock just above the hips, change levels, hip into them, solid back arch and dump them on their head. Throw your leg over, rip your stick out from under them and go to work. I've done this exact move numerous times in sparring and I usually achieve something close to a knockout from the landing. It will at the least stun them long enough to let me gain the advantage. I have also been on the receiving end of this and it always reminds me of the reason why I prefer the Underhook.
With the overhook I can only control them from the neck up. With the underhook I can control them from the waist up. With the underhook I can stop their takedown, with the overhook I can't.
Peace,
Paul Sharp
http://www.championjiujitsu.com