Wireshark running on a server seeing lots of `ARP who has` with different tells

This is normal, especially if whatever at 10.10.0.40 is turned off or disconnected. For example, if 10.10.0.40 is a DNS server and everyone is configured to use it as their primary DNS server then you will get a lot of machines asking for that address. But since it's not on, they will ask a lot and get no response.

That doesn't look out of the ordinary to me, assuming that your 10.10.0.40 address belongs to a sever / printer / other shared resource and your users are on the same subnet & switch.

As suggested by Tim Brigham, this is not out of the ordinary. The devices are doing ARP requests to get the MAC address (layer 2 address) for the 10.10.0.40 address. By having the MAC address, the hosts will be able to connect to it directly, without having to include a Layer3 hop.

For example, if all hosts are on the same subnet and same switch, the machines can connect to 10.10.0.40 without going to a router first (which is necessary for connections on a different network).