Thanks jsa - I appreciate it! Yes, I was able to ping from one to the other after editing /etc/hosts *AND* editing the eth0 file in the /etc/sysconfig/network-scripts directory per the above (& the referenced link). Now I've set the gateway. So I think I'm on my way! 
Also, I will look at /etc/nsswitch.conf in the virtual machines per your suggestion.
finally, as a final comment about Tiny Core Linux, I was able to edit /etc/hosts and ping the multiple IPs; however, setting the hostname (in both /etc/sysconfig/network [hostname=namenode] and in /opt/bootsync.sh) would not keep the hostname in tact when I rebooted. And if I ran bootsync.sh after doing "sudo su", it *did* change the hostname, but then after I exited my current session, I was unable to open another terminal window or even hit the "power" icon to shutdown or reboot).