Yeah I meant a better compromise would be to make Disrupt replace Pummel in the literal sense, ie Pummel becomes an AoE rupt at the same CD.
You gain something significant from the talent (as opposed to a little dubious), but lose the ability to rapidly chain 2 interrupts. Piercing basically grants an AoE Hamstring, so getting an AoE Pummel as the alternative sounds reasonable.
If 10yd radius 4s rupt every 15s is too over-the-top (I'm sceptical, since it still requires making sure everyone is silly enough to clump around a Warrior and stand around casting instead of fleeing in opposite directions), tweak it as necessary: lower radius, put on GCD, reduce lockout timer, increase CD to 24 / 30s to match other ranged interrupts, etc etc etc.
It just feels a little bad as a counterintuitive talent where you need 2 binds to choose between two abilities with shared but different cooldowns that do the exact same thing in most situations. Kind of Shaman Shock Syndrome, but at least with Shocks the CDs are identical and you're just choosing between very different options.
This is like having Frost Shock (6s), and then AoE Frost Shock (30s), and they both share a CD, except the CD works differently depending on the order you use them, so you have to track both separately anyway. Functional, but awkward.