Tended not to; there'd normally be one 'artist', maybe two on the Staffel or Gruppe, who would use the same style throughout. Although I can't confirm it, I believe that the style of numerals was standard within a Geschwader, certainly within a Gruppe, and tended to be (but not always) one of the few 'approved' design styles. The numerals to look out for are normally '4' and '8'. The former could be closed or open, whilst the latter could be round or 'squared'. Whichever style was used, would determine the rest of the numerals used. So, if, for example, you saw '8' and maybe '9' as rounded, you'd know that any other 'curved' numeral, 2,3,6 etc, would be in that style.
If you see an open '4', it is more than likely that '1' will have a longer 'tick' stroke, and '3' will probably be 'flat' on top, and so on.
Not a very positive way of ascertaining styles, but normally works!