The game isn't being over run by thuggery so I don't think it's required but if it were to be brought in, I think the following stipulations must apply:
Must be given by a video referee (like they can be in soccer). Umpires on the filed don't give them.
Can only be given for acts which are not attempts to carry out a legal action e.g. cannot be given for poorly laid tackles, bumps or spoils.
Examples of red card offences - Gaff hit, Lewis hit (2017), Bugg hit (2017)
Non red card offences - Nic Nat Tackle, any of the number of head high bumps that got weeks.
Basically would mean red cards are given for off the play punches to the head in the majority. I'm fine with that.