Runeglaive Gragas?

So if the 5.16 patch nerfs both armor and cinderhulk I feel like going AP gragas over tank gragas may actually become a thing again. I figure his W scales down to 4 cd before cdr (2.4 w/ 40%) so it will proc runeglaive every time runeglaive comes up, and his AP ratio clears 2 on a full combo so it's not terrible (plus W gives some dmg reduction and you can probably fit hp in the build with liandry's at least). Am I way off base thinking AP grag may out perform tank grag if cinderhulk goes from 25% to 15%? Also what would you think for builds on him? My guess is runeglaive followed by liandry's/rylai's or morello's/DC for increased HP/Pen/slows on the first and more CC through the lower cooldowns + higher burst on the second option.