You could also just look at the previous damage model. Rock throw did ~800 damage if you combined Splash and Direct hit damage. Look at a 2 striked hunter that gets hit by a rock throw. They have at max,
(1600 x 40% = 640hp) [Each strike = 20% max HP]
1600 - 640 = 960hp when 2 striked
A Rockthrow with 10% damage increase would almost kill a hunter with 2 strikes at full hp. This is only achievable if Direct and Splash damages were both applied and ~800hp damage was incurred. Otherwise you would have ~320-400hp damage [Don’t remember exact value]. Which would leave you with half your HP bar after a single rock throw with direct hit.
I just felt like doing some math…