Zero risk is easy to understand and makes nice slogans, but there's money to be made in managing non-zero risk.

There is zero risk and infinite risk. Betting your company on another company and having no exit strategy available (or possible) may be lucrative, for some time, but, in the end, may prove quite painful.

My advice would be to manage the non-zero risk and ride the other company for as long as you can, but keep Plan-B always in hand.