I would like to have two separate leads and deal layout. For example, a service lead converting to a deal and a sales lead converting to a deal. Both will have different stages and fields. 

I have one lead and deal layout added and mapped currently. However, when I clone my existing layout and go to edit the deal stages I see a warning 'changes made to the stage name, probability, forecast type or forecast category of an existing stage will be reflected across all the layouts'. Does this mean I am unable to have two separate lists of stages and or probability? 

Having read the help articles it advises that you are able to have more than one set of layouts with differing fields. So what is the warning all about?

Any help would be greatly appreciated as I don't want to mess up the existing leads/deals we have in place.