Anyway, I think the "A" teams should be involved more in this cause. If there are 2,3 or more tiers I would love to see the stronger teams "A" teams involved eg. Aus, Eng, Ind, SA, maybe SL if they have the depth. The only rule would be that "A" teams could never be allowed into the top tier.
You could have the top 8 in Tier 1, then Bang, Zim, Ire, Neth and the 4 strongest "A" teams in tier 2. That would keep the 2nd tier of a pretty high standard. You could even keep going in a 3rd tier, with the "A" teams from the other top 8 teams (SL,NZ,Pak,WI) along with another 4 associates (Can, Sco, Afg, Ken). The trouble is that when you get to the lesser teams a lot of them are amateurs and can't afford to tour constantly. So you either need to make the tiers smaller, or make they play each other less often.