Having previously spent a decade in that role for a $1B company: I never got a veto right before stuff got sold to customers. I really, really wanted that in the beginning.

In the end what I ended up doing was spending a lot of time packaging the product as well as educating the sales force. If you don't have well-packaged products, the sales force will sell anything, even if it doesn't exist. And they'll get backed up by a typically slightly disconnected exec team, because they also want revenue really, really badly.

This strategy worked surprisingly well. I think both the sales team and the ever slightly disconnected exec team benefited from the artificial structure that I spent so much effort making up. I guess people instinctively just like following clear structures over chaos.

(This was 5-10 years ago, and not in Silicon Valley.)