External number ranges of assets

Good day experts

Our group of companies are currently using internal number ranges for assets. All these companies are on the same client.

We are experiencing problems with workflow notication (PM) for assets not working. Similar asset numbers are creating in different companies within the group. Company 1 and Company 2 having an asset with a number 300012. The workflow is somehow failing.

What is the possibility of external number ranges for assets? As we had been using internal numbering what will be the effect if we start with external number?