Following a consultation with my former employers favourite consultant, our setup ended up like this:

 

Server 1

Server 2

Server 3

Server 4

Server 5

Domain Controller

X

 

X

 

 

DNS

X

 

X

 

 

DHCP

X

 

 

 

 

Global Catalog

X

 

X

 

 

WSUS

X

 

 

 

 

Operations Manager

X

 

 

 

 

Schema Master

X

 

 

 

 

Infrastructure Master

X

 

 

 

 

File Store

 

X

 

 

 

Printers

 

X

 

 

 

Sharepoint

 

X

 

 

 

SQL Server

 

 

 

 

X

Exchange

 

 

X

 

 

ISA

 

 

 

X

 

RID

 

 

X

 

 


There were 3 more servers which ran specific services, but these were the main 5.