Looking for thoughts on connecting 3 buildings around town via leased fiber from local ISP

So we have 3 locations that we will be connecting via leased fiber from the local ISP (no ethernet/routing services from them, just a fiber port to connect to), and I am wondering about layer 2/3 on the remote sides. The main location (which is where the servers are that the remote locations need access to, and where the internet gateway is) has a layer 3 switch that we will use to connect the 2 remote buildings, but on the remote side do I NEED a layer 3 switch, or would I be just as well served by a layer 2 switch. These remote networks are flat - not vlans. I envision a VLANed port on the layer 3 switch at the main location for the fiber connection, and DHCP helper to get services to the remote buildings. If I should do a layer 3 switch at the other end, tell me why. Thanks.