I think I've reached a point where I can no longer think clearly

Honestly, like you, I guess I'm not too fuzzed if AV9ers become relatively a little better off than before. I mean, they're still taking the brunt of the effect of claw, so they're still getting hurt. I suppose for me the main issues are to make sure that the damagelevel against AV9 doesn't dip too low (POMB), while at the same time making sure that the damagelevel against AV7 (and clawvictims) drop significantly.
For me, I figure shaving roughly one third off everything would get us some pretty good damage levels.
I took the time to look at a lot of the numbers we've been spitting out, and I pretty much have some minor issue with each set. That either means to come up with something new, or to just accept one of those issues and move on.
*I don't think the CAS-rate should drop below 10% against AV9 when POMBing.
This to my mind kills 'PO is RR on INJ & MB doesn't stack'
*I also don't think the CAS-rate should be above 20 when POMBing AV7 (or CPOMBing)
My own original PO=+1/+1 falls to this, because the CASrate against AV7 is 24 or so.
(So does pure CRP, which has it at almost 27)
*Piling On on the armor roll is tricky, because, as you say, the stats get unreliable, because sometimes piling on against AV9 isn't worth the risk. On the other hand, piling on against AV7 usually is. I don't much like MB not stacking with a PO on AV, because that compounds the situation - because piling on to roll a 10+ is bad odds. And as stated, I don't want to give AV9 too much of a helping hand. To add to the trickyness of the situation, some coaches will just pile on every time, in order to get the most out of their killstack - so they will wring every last drop of blood from the combo. It is simply very hard to figure out how strong AVrerolling is in reality.
*Then again, I'm not too crazy about any non-stacking solution, because stacking is an easy to remember rule for all skill-use.
- which is almost a shame, because 'nothing stacks' gives some pretty good numbers all round - except it has a casrate against AV7 at almost 24, and that is way too high.
I have toyed with a rewrite of Piling On, which, IMO, produces some pretty good stats. It has (to my mind) the advantages of not preventing stacking, seeing the dice before using (so there is no uncertainty about how it will affect AV9), keeping AV7 Casrate below 20, and keeping AV9 Casrate above 10. Also, while this retains Claw as a weapon to keep High AV teams in check, it reduces CPOMB to a level similar to LRB4, where, as I have shown, AV9 teams were quite viable.
The stats are:
PO: AV9 13.3/6.0 AV8 17.9/7.9 AV7 (or claw) 23.4/10.4
As this is actually weaker as a stand-alone skill than Mighty Blow, it is worth noting that I've removed the risk to go prone for no effect. You will at least get a stun, when you place yourself prone.
POMB: AV9 22.2/11.2 AV8 29.1/14.7 AV7 (or claw) 38.2/19.2
(Unfortunately, it's a complete rewrite, so I have a hard time seeing it gain acceptance in house rules like NTBB - it would have a better chance of just being ruled straight into a future edition)
Anyway, I can't help but comment on your list to Dode.
As stated, no real problem with that.2.The benefit I'm suggesting is to Av8 and above which means teams like Humans and High Elves benefit as much as Orcs or Dwarves do.
Hmmm... Weakening Claw might mean that it gets taken last. But 'diversify' might be wishful thinking - I think the full stack will still appeal to coaches, even when it is weaker. (Not that that is a problem, the stack is fine if it isn't overly potent)5.It stops Claw having a greater effect the more kill skill you stack on top. Hence encouraging claw access teams to diversify their skill selection.
They are indeed.1.Dwarves and Orcs ( ) are already getting directly penalised.
Agreed. Movement away from Chaos would be nice. And I think that the awesome bashing power that Chaos has under CRP is what has made Chaos so damn popular. Once the power of the stack is reduced, the metagame will change entirely, and I can't see why orcs and dwarfs wouldn't be back in prominence.3.Orcs and Dwarves don't appear to be more popular than Chaos in most long term leagues, and if anything the opposite is true. So movement away from Chaos is a good thing.
But these guys start with a lot of skills. And without the same fear of the stack, they can run with a pretty shallow bench. Bottom line: They don't need to go above TV200 to be good teams - unlike Chaos, which starts with no skills (and AV8 linemen). They'll be fine even though the roof comes down a bit - certainly still very playable.4.Even if it does result in more Orcs & Dwarves, more punitive spiralling expenses make it harder for them to get very high.
But if you nerf both Piling On and Claw, aren't you nerfing the POMB teams only once, but CPOMB teams twice?6.I'm only proposing an additional change to Claw, which is most easily available to 3 bash teams (Chaos, Chaos Dwarves & Nurgle) which makes their hitting power reduce proportionately to that already proposed for non-claw teams.
Cheers
Martin