The yellow card/red card dichotomy is kinda ridiculous in soccer.
Yellow - basically no penalty at all outside of a free kick.
Red - severe penalty, sent off for remainder of game.
And the problem is that there is a very fine line between the two. Makes no sense, maybe they should increase the penalty for a yellow, maybe off for 10 minutes. Save reds for really egregious shit.
That's what rugby does, definitely feel like it would be a welcome change in soccer. Rugby is stop clock though.