ps - it is usually memory that is the resource bottle-neck in a host. CPU can also be, but it is much less common. However, if you give VMs multiple CPUs and they do not actually require them, then you do complicate the resource allocation issue - it has to do with available CPU time-slots. When a 2 CPU VM accesses CPU resources there has to be 2 physical CPUs ready for it.
Whatever - really unless your other VMs are very CPU intensive, you likely will not have to worry about CPU resources - but the amount of host memory is not that large, so simply make note of how much is available when the existing VMs are running at capacity, to determine whether there is enough available to squeeze another server in. Even though you have "allocated" a bunch of memory, much of it in one or more existing VMs can probably be ballooned and given to the new VM ....
The glory of VMware ....