Stagger commercial lease dates

[Joseph Parker]

I'm currently under contract on a smaller, 5-unit commercial office/retail property. 4 of the 5 leases expire in April/May of this year, and one of the contingencies of the sale closing is that 3 of those 4 soon-expiring leases renew for at least one year (I have full negotiating power over those leases).

All of those tenants have showed no intention to vacate, and are happy with their current situations.

I've seen/read in many places that it is best practice to stagger leases as much as possible in order to avoid the possibility of multiple tenants moving out around the same time, leaving numerous units to be turned over.

Would it best for me to try and get 2 of the 4 tenants to renew a two-year lease (which they've done in past) and the other two tenants agree to a one-year or three-year lease (both have been year-to-year in past ). That way I'd have staggered years and less risk of multiple vacancies at the same time...? 

These are mainly mom and pop businesses, so any longer would probably not be likely. A couple of the lease rates are below market rent/sq ft, so while I'd like to bump those up a small amount as they've never been raised, I also don't want to immediately have a bad reputation with those tenants.

Suggestions or past experiences?