Sharepoint List Flow - 4 Data Points

Hi All, 

I have been asked to add some intelligence to a couple of SharePoint lists; 

List 1: A list of Users

List 2: A list of Laptop Assets

List 3: A list of Mobile Assets

List 4: A list of Mobile Numbers

Originally I thought I was being clever just setting up lookup columns for each expecting the data to auto exchange, of course this is not the case.  I have attempted to create a flow which does exactly this but I have found that Flow doesn't take any lookup parameters into account.

I just want to understand how data can be exchanged via sharepoint using flows. I have looked around and seen plenty of confusion around the Dynamic Content within Flows for SharePoint. 

The Idea is that any items that have been updated will update accordingly to the relevant list.

User Asset Change > Asset List updates > User List updates etc. 

Any references would be great, can't say I have found any information on how this intelligence works. 

Kind Regards.

Rob