Hi, Welcome to Basenotes!
Deodorants are for masking body odor, while Antiperspirants are supposed to help you not sweat as much. Cologne can be worn along side either, and as long as the deodorant isn't too powerful, they shouldn't clash. However, just in case, many of us choose to use an Unscented brand of deodorant/antiperspirant such as Mitchum.
Usually, the supporting bath products are used both to accentuate and support the main product and are often very similar. There are some exceptions, such as Yves Saint Laurent's M7 range. Each product focuses on a different note and smells slightly different. But, for the most part, Basenoters seem to just use the cologne. (Less money spent on supporting products, more money for MORE cologne!)