Lots of different reasons to have it one way or the other. What is the layout inside the building? As said above, shortest trip to the house. Me I put in the 48" wide door around the corner, but it allows me to move long stuff directly through the machine shop into the main garage. What you do in the building, work flow, people flow, and land layout all play in the reason of where to place the door. There is no reason to key the man door placement off the OH door. To many other things have a priority in dictating the placement.
The above is in my build thread below. The man door leads to the machine shop, and on through to the 'dirty' shop.
lg
no neat sig line