I tried for a long time to play rugby, alas quite inadequately. I liked it cos there were no bats, stumps etc to lose just a mis shapen pigskin. You had no need to either know of or be able to understand the rules. for me this was a great advantage. I just pushed the opposition around or got vaseline and horse oils in their eyes in the scrum. One thing i did eventually learn was that if the Ump told you not to do something, you got a smack in the mouth for being stupid.
If the current crop of internationals ignore the Umps clear instructions, hands out, stand back, wait, etc. the Ump should be allowed to deck them for being stupid and getting paid for it.
At my dump of a Sec Mod the head had delusions of grandeur we had to follow the code of his Alma Mater for Refs. They wore ties and blazers, and had to be referred to as Ump. Particularly if they had just jogged you a shorty.
Steve.