Physical Network Design for VMware vSphere Based Site

So we're currently building a small site. Basically we'll have 2xC9300s and 4xESXi servers (clustered in a vCenter).

In terms of layer 2 design, there's a lot of debate going on. Some say we should keep the physical network flat, so everything on VLAN 10 for example, and strictly create VLANs within the vCenter. Others are arguing for the creation of multiple VLANs on the physical switches and assigning the server's NIC respectively.

The goal is to keep it as simple as possible.

Any advice about L2 best practice for this scenario?