There are a few mods that add realistic traction so vehicles with small wheels will easily get stuck in a soft, tilled field which makes contact area important, especially with tracked vehicles that have superior traction with very little ground pressure. Same goes for planting and harvesting rowcrops the rows on the respective tools and harvesters do not have to line up with the crop. Unlike in real life, however, the wheels do not need to be lined up to travel between rows of planted crops.
Starting since 17, you need thin wheels to avoid flattening crops if crop destruction is enabled.Acceptable Breaks from Reality: Many of these examples often have mods that let you avert this if you wish to add a bit more realism to the game.