No. Sequel Data Warehouse is a tool that is designed to build and manage data warehouse tables, and the ETL processes that will load these tables - so Sequel Data Warehouse users are developers in every sense of the word, however it is not necessary to be a programmer to use Sequel Data Warehouse.
In fact you could say that Sequel Data Warehouse itself is the programmer, since the Sequel Data Warehouse software actually writes the source code for the tables, indexes and ETL programs, and then compiles them for you.
Sequel Data Warehouse is designed to remove you from the underlying complexities. All you need to do is use a very intuitive and easy-to-use visual designer and business rule editor.
Having said that - is it an advantage to have one person on the team with some programming experience? Yes it is. That background and experience can help as far as understanding database concepts, and formulating rules (e.g. using if-then-else logic).
If you've used formulas in Excel, or developed queries in Query/400 you probably have the skills required to be a successful Sequel Data Warehouse developer.
It's actually far more important that you understand your business needs than it is for you to be a programmer.