There are two questions here, one for MS clustering, and another one for Mongo.
MS Clustering
The decision of where to put the public, heart-beat, inter-node communication, and quorum drive is significant. Also cluster architecture makes a difference; you pick different quroum options if the two nodes are in adjacent racks than if they were in completely different datacenters.
Put the heartbeat on the same interface/subnet as the public interface
This theory holds that if you lose your public interface, you want the heartbeat to fail because this node is effectively down to users.
Put the heartbeat on it's own private interface/subnet
This theory holds that something outside of the cluster is arbiting who is doing what role, and unnecessary node-death is to be avoided.
Put the WFS on the heartbeat network
If the two nodes are in the same overall network (the same set of switches is supporting the non-public networks for both nodes) then putting the WFS on the heartbeat network doesn't introduce any new vulnerabilities.
If the two nodes are in different network fault domains (such as different datacenters), this is a bad idea. The heartbeat network provides the 'node majority' quorum option, and the WFS provides the 'File Share Majority' quorum option. You really want both options to be in separate fault domains.
Your revised diagram makes sense if both nodes are in the same data-center, though I myself would but the heartbeat on the public side.
MongoDB
MongoDB is a bit simpler. With even numbers of nodes, you absolutely want a third node to act as tie-breaker. They're pretty clear about that. However, your diagram states:
Up to 12 replica members (7 can vote).
7 is an odd number. You don't require an Arbiter.
Unlike Microsoft clusters, Mongo's cluster voting doesn't care about multiple avenues of network to break voting deadlocks. Because of this, separate arbitration and cluster-internal networks do not provide any meaningful increase in robustness. The only reason you'd want a separate arbitration network is if replication traffic was expected to be so heavy that election-packets (the heartbeat, actually) would get pushed so far down the stack that it would miss the 10 second timeout.
Best Answer
The book is correct, however there are pieces it left out.
The procedure followed by clustering software to create a service based on a virtual MAC address is pretty straight forward. When the service comes up, it offers a Gratuitous Arp packet saying that the specific IP address can be found on the virtual MAC address. When failover happens, the 'down' node removes its local IP/MAC binding and the new node starts listening to that virtual MAC address and IP combination. No muss no fuss.
The other method used by clustering software is to not bother with virtual MACs at all and rely on Gratuitous ARP the whole way. The startup/failover sequence for such a system would look like:
In my experience the second method, pure G-ARP, is the one used by most linux clustering these days. However, both methods are valid and have been used. The benefit of the G-ARP method is that you don't have to muck about assigning virtual MAC addresses. The benefit for the pure virtual-MAC method is that it doesn't rely on G-ARP working on a given subnet.