Big dog could just easily pretend he's 35 different persons all mining at 1% of the net hashrate to avoid the 'tax'.
How would he be able to split up into 35 people. I think he would be spending more money just to avoid a tax.
Mining on different pools, or using more pool accounts, using different proxies, the possibilities are endless.
If this is a problem of scarcity, then why not just make a coin that gives a random number of coins per block. Maybe between 1-100.
This coin won't fluctuate like the others, making it stable and easier for investors to get their money hungry hands on it.
A random block reward between 1 and 100 is an average reward of 50 so that doesn't really change anything.