I'm not sure that your example makes sense. Suppose a scenario in which there are three miners with equal hash rates and a protocol which emits 3600 coins per difficulty period. The division of coins will be approximately 1/3 per miner when everyone is running. You're a miner and decide to enact your strategy.

What happens is that in higher difficulty periods your competitors who keep running constantly are making 1800 coins each. When the hash rate drops and you come on everyone gets 1200 coins each. Your expected revenue becomes 600 coins/period. The result of your strategy relative to just running constantly is halving revenue.

The only variance introduced is the speed at which new blocks are generated in each period.