[Youden]

English is a living language so it's impossible to say definitively that you're "wrong" but I don't think anyone else is able to understand what you're trying to communicate through your use of this word.

According to the Cambridge dictionary, there are a couple of variants depending on your dialect:

- "to make something else seem better or more attractive when combining with it" - e.g. "Strawberries and cream complement each other perfectly."

- "to help make something or someone more complete or effective" - e.g. "She used photographs to complement the text of the news story. "

The only way I can make any sense of your words is to assume you're trying to argue that two competing but interchangeable services "complement" each other when used simultaneously because that might allow a customer to mitigate risk in a similar fashion to a multi-cloud setup. That's a pretty big jump to make from what you've actually said though and would really need further explanation for anyone to understand.