The position, size and form of the Balkenkruez varied widely between the different divisions over the war. Camo patterns and added equipment like the track cable also comes into consideration.

There's no political consideration regarding it, unlike the swastika which is illegal in some areas. My guess is whatever tank you have is modeled on an actual one that didn't have it on the hull. Trumpeter was never shy regarding decals, even releasing swastikas in kits for NA release.

In terms of the numbers, the digits just identified it's position in the company, down to which platoon and individual tank it was, mainly for radio identification and again was up to each division how and where they marked 'em. For the most part, it was a three digit system, sometimes including a letter for company command.