I too like Clay, I have slightly different cards…
Reflect Shredder I find largely useless since, as you said, flyers stop shooting at Clay, it is extremely hard (not impossible) to get them to do it, it’s not worth it for me… and I find that I can recharge his ultimate with the regular mulcher, I don’t need the charger card…
I use mulcher damage, heavy capacity, cryo, torquebow bleed, and explosive stun.
I find the 200% cryo highly effective, especially with 215% ammo, so I live the first 10 waves on basically dropped heavy weapons, especially the cryos… There are LOTs of those, usually… and if we get robots, then salvos on 4…
I find that an active torque head shot, with my level 4 bleed and max damage perk does about 18,000 damage (including the bleed), so I find that is a good weapon against scions and DRs, until I get my mulcher and salvos (I typically use a single quad locker, with 2 salvos, 2 mulchers, and a cryo). With 2 mulchers I don’t need to worry about the chaingun ammo regen, I can upgrade the ultimate duration which I find to be much more help to the team in the early 10-15 waves (I can freeze dangerous enemies without getting downed)…
But the nice thing is, there are many ways of play with Clayton, so there is no right/wrong way, just whatever everyone prefers…