Why we have the release order dependency on bill group functionality

Hello,

By using the standard bill group functionality, we can generate multiple draft invoices at a time.

But when it comes to release, I found that there is order restriction on draft number.

Ex:If there are 2 invoices, draft invoice1 and 2. If I tried to release draft 2 first,system is not allowing to do such action.

Practically, user we cont expect the  user to release the draft by order when we have multiple drafts.

Can anyone knows why such restriction is there or what might be the reason behind such restriction?

Regards

Raju