How to fill in a score-slip is a matter for the sponsoring organisation. In practice there are many different ways. It tends to be different in different countries, not just Zones.
You have a perfect right to insist on your players doing it in a particular way. After all, your club is the sponsoring organisation. But why do you want to? As a scorer, you ignore the number of tricks made nearly all the time, do you not? You just take the score.
If you really feel it is important to get some consistency then I suggest you get travellers with a column headed "Number of tricks". People will tend to fill that in consistently.
As to the examples you offer, if someone makes 11 tricks in 4
+5 is the North American notation, 4
+1 is European - I do not know why you put "even" for a method used by hundreds of thousands of bridge players!
As you say, some people say 4
made 5, some 4