Multiple Service resource allocation

Hi all,
in service mgt. module, in the service order allocation lines, it is possible to allocate only one resource at a time per Service Item Line. It is not possible to allocate two different resources with status Active to the same service order line. There is some standard code that raises and error if you try to do so and in the Navision service mgt manual, there is an Note describing this fact.

Now I'm trying (without success) to understand reasons for that, and I sincerely think that for a service company it's normal to allocate more than one resource for the same job.
Do you have any idea about this?
Has anyone already tried to remove the standard check? If yes, which were consequences?

Thanks for your answer and help
bye