However I find 2 weeks for an attempted head butt where he really had a crack but happened to have shit aim to be absurd.
"I was trying to headbutt him in the chest because I knew it wouldn't cause injury. Do you really think I'm crazy and was going to headbutt someone with force in the face and miss the whole season?"
So for a headbutt, it may be 5 weeks penalty, if you do no damage you immediately start the 5 weeks, if you mange to connect and break a nose and the victim is out for 2 weeks then you essentially would get 7 weeks, wait 2 weeks prior to the 5 week penalty starting.
(g) the effect of the Player’s actions on the victim (for example, extent of injury, removal of victim Player from the game);
What happened to the victim is one of the considerations as to the seriousness of the charge.
I don't think you can reasonably make it the driving force behind suspensions because of the imbalance that would result from similar actions.
Overall I think all of these different cases show how tricky the whole disciplinary system is.
The one thing that I would be in a hurry to change for World Rugby is to reduce the headline suspensions for most categories but then subsequently reduce the number of weeks available under mitigation. This is assuming that World Rugby is happy with the general level of suspensions that the various judiciaries are handing down (and I don't think there is any evidence to suggest they aren't), but the fact that rugby fans complain about this almost every single time suggests that it could be improved.
In criminal trials you get a reduction for pleading guilty at the first possible circumstance because it saves taxpayers a lot of money. That really isn't the case here. The judiciary still goes through the process determining the level of the charge and the subsequent sanction. There's not a dramatically shorter process because the guilty plea.
If three weeks is the final sentence you want to arrive at, have the penalty start at four weeks and reduce it by one for the guilty plea and remorse. If they challenge it and lose they get 4. If they have a tarnished record they get 4. If they have a bad record they get 5 etc.