Unused servers deletion in BI 4.0

Hi,

We are not using crystal report in BI 4.0 and not in future.our BI 4.0 environment scopre is for webi and xcelsious on top of SAP BW & Oracle..

If we delete crystal reports servers in CMC then any impact on webi reports & xcelsius?

what is the use of connection server in the CMC?

What is the use of four dashboard servers in the BI 4.0.?

or how many servers we can delete as our present and future scope is limited with Webi reports & xcelsius only.

Please let me know if need more details.

Thanks,

Amit