How can one run mutiple idrac 5 cards on the same network?

Port forwarding.

How you implement this depends on the model of your router, but almost all firewalls/routers will do it. If yours doesn't, you are using the wrong model :)

publicipaddress:externalport forwards to internalipaddress:internalport

If your public IP was 95.85.75.65 and your DRAC's are on 192.168.1.20x, you could do:

95.85.75.65:5001 forwards to 192.168.1.201:443
95.85.75.65:5002 forwards to 192.168.1.202:443
95.85.75.65:5003 forwards to 192.168.1.203:443

I dont believe my router will alow the port to be opened twice on different IPs

You aren't "opening" 443 on the inside - internal ports shouldn't matter at all. You are forwarding an external PORT to an internal ADDRESS. On the outside, for a single public IP address (95.85.75.65), you can only use 443 ONCE which is why you use different ports on the public side, then "translate" that to a different port on a different address on the inside. Even my $40 Netgear router at home can do this, so if you are running a business behind a firewall/router that cannot do this, I'd recommend a business-class router. What model router do you have?