Buy new residence/future-rental after 1 year or 2?

[Braden Anderson]

Wondering if I should buy a new residential (future rental) house after 1 year, or 2. 

I just bought a townhome in March, 2018. I have originally been planning on living in it for 1 year, saving up a down payment, and then buying a new house March 2019, and turning my current townhome into a rental property. Then doing the same thing for the next 4 years. That way, I can acquire a new property once a year, for only 5% down. HOWEVER, I just came to realize that if you stay in your primary residence for 2+ years, you don't have to pay capital gains tax on it when/if you sell it down the road. This made me second guess the above strategy and think about sticking it out here for 2 years, and then buying another townhome. What are the pros/cons to each??