How create generic wsdl that consume anothers wsdl

I'm trying to create a generic wsdl with the goal to add or connect / communicate other wsdl to have a single unified web service. Is it possible to do this? What I could do is a web service that in one of its functions calls or instantiates a client from another ws and returns the data as if it were running a normal client to that url. The issue I'm noticing now is that the response times are tripled for each request the generic ws performs to said url.

Is there any way to implement this in a better way? good practices?

I want to do it this way for a topic of confidentiality of the service, for this reason I can not directly access the url.

In the technical aspect said wsdl I did it with php using the lib nu_soap

Any suggestion? Thank you