I played the original version of Axis & Allies made by Milton Bradley released in 1980s way back then. Can anyone explain the reason for the changes to the game after Hasbro/Avalon Hill released the later versions?

1. Why do tanks defend at a roll of 3 or lower instead of 2 or lower in the Hasbro version? Is it not obvious that tanks are more adept at attacking than defending? The MB version had tanks attacking at 3 or lower but defending at 2 or 1.
2. Why are the German pieces black instead of gray as in the MB version? Gray was the color of standard uniforms for the German army in both world wars. The only German units that I know of that wore black were the SS. Even then, I think that only the formal uniforms, not combat attire, was black for the SS.

Any ideas or answers from anyone?

I played the original version of Axis & Allies made by Milton Bradley released in 1980s way back then. Can anyone explain the reason for the changes to the game after Hasbro/Avalon Hill released the later versions?

1. Why do tanks defend at a roll of 3 or lower instead of 2 or lower in the Hasbro version? Is it not obvious that tanks are more adept at attacking than defending? The MB version had tanks attacking at 3 or lower but defending at 2 or 1.
2. Why are the German pieces black instead of gray as in the MB version? Gray was the color of standard uniforms for the German army in both world wars. The only German units that I know of that wore black were the SS. Even then, I think that only the formal uniforms, not combat attire, was black for the SS.

Any ideas or answers from anyone?