How scale the services for 4 SharePoint 2013 servers?

Hi,

I have in my new farm 4 Sharepoint servers. We are more than 1K users but less than 20K users. 

WFE1 just with IIS

WFE2 just with IIS

APP_Serv1 with CA and all the services except for Search Services

App_Serv2 with just Search Services.

Is this correct? Is this considered best practices?

Thanks.