Hello, I would echo the comments from Wright-Fi, with some additional comments/considerations below. I can tell you first hand that an all mesh deployment in your scenario is going to be more of a headache than it's worth.
Each mesh link is called a 'hop' and each hop reduces throughput by about half. We don't recommend going more than 2 hops deep. Best practice would be to use a dual radio AP, with one radio (typically 5GHz) dedicated to the mesh backhaul (hop), and the other radio for client access. While a single radio AP can also do mesh (backhaul and client access on the same radio), it is highly recommended that you don't do that.
Each wired AP within a mesh network is called a 'root-AP/Bridge'; each mesh AP is called a 'non-root-AP/client'. You need 1 root-AP at a minimum, but a more robust mesh network would use 2 or more root-AP's for a back-up connection into the network. You can see that one of the considerations with mesh networks in general is the single point of failure with only 1 root-AP.
Mesh is useful for 'one-off' AP deployments (i.e. the far AP in the warehouse), but is a serious pain if you want to get the entire facility up and running.
Also, I would hesitate on using the E400 in general. The E410, E600 and even the E430 (great solution for conference rooms) would be better choices.