A suggestion for rebalancing Gangplank

OK, as you may or may not be aware, Gangplank is staring down the barrel of a pretty major nerf on the PBE, changing his barrels from ignoring a large percentage of the enemies' TOTAL armour to only a percentage of their BONUS armour. It's pretty obvious what the problem is; GP is simply ripping through squishies far too easily, especially AD carries, which isn't what Riot had in mind when they were redesigning him.

Now I just had a thought: if you ask me, the REAL problem with the barrels lies in chaining them, particularly the way doing so not only allows GP to bypass the ENTIRE "can you defuse the barrel before he detonates it?" minigame that the skill was designed around (by shooting a barrel you can't even reach to trigger one that you can't defuse right on top of you), but also allows him to trigger his MASSIVE bursts of AoE damage on enemies who are not only out of his melee range, but even far out of the range of his Parrrley (Parrrley has a range of 625, but GP can place barrels as much as 1000 units away)! Clearly Riot are nerfing his AR pen to try and inhibit GP's ability to do this on low-mobility squishies who can neither get out of the explosion radius without Flashing, nor stop him from triggering it because the barrel he shoots to set the chain off is far outside their attack range. However I don't think this actually addresses the problem.

What I think would make more sense would be if each chained barrel does reduced damage compared to the first one. For example, if the initial barrel Gangplank triggers explodes for (just throwing out some completely random numbers here) 1000 damage, the first one it chains to will only do about 800, a 3rd barrel would explode for only 600 and a hypothetical 4th barrel in the chain would only do 400. This would cause the ability to do more damage to enemies who charge in on Gangplank to take him on face-to-face, while not punishing the squishies who are trying to kite but failing because GP is only technically a melee champion (let's face it, almost ALL his damage at the moment is coming from the barrels). Basically it would punish people who fall into GP's traps, but not allow him to just project long ranged damage like he's a goddamn Xerath in a pirate hat.

What do you guys think?