In theory yes, but we will not build one like that. It is because if we use a DEXTER personal cluster in cluser mode the best performance can only be expected if all workstations have the same main components. Cluster mode means that all workstations have the same Operating System and software package on and you run distributed computing on all or some of the nodes.
If a motherboard, a processor or memory type were different (slower) from the others this slower node would be the bottleneck of the whole system.