What is the criteria for planning system to combine multiple demands into one planned order?

Summary:

What is the criteria for planning system to combine multiple demands into one planned order?

Content (please ensure you mask any confidential information):

We have multiple Sales Order or Transfer Order demands in the system for which we have to procure raw material (Buy items) in order to complete FG item (manufacturing). And it is combining demands that are having very far due dates with demands that has near due date. So, business is asking why planning is combining all of them into one and suggesting to procure now itself? Why can't it create multiple planned orders with different due dates, so I am trying to understand, what could be the criteria for planning to combine different due date demands into one, thanks.