So to maximise Neb airdrop I'd be better redelegating all to a single tiny validator than my current strategy of splitting between about seven validators many of whom do useful services for the community.
Algorithm for distributing rewards per delegation is:
X / N * M
X = total NEB airdrop per the week
N = total number of validators except top 5 (105)
M = my delegation to that validator
So airdrops valid even if you have some stake to top 5 validator, just get less