Who is more important, marketers or engineers?

No problem if you are asking: "who gives the greater contribution?" (personally I would answer engineers, and I am a non-technical guy!), but if you are seriously trying to figure out who is more important, you have gotten it all wrong and you are also making an ethical and practical mistake.
It’s an ethical mistake because you are potentially planting the seeds for childish debates instead of helping your team focus on getting the job done.
It’s a practical mistake because marketers and engineers are part of the same organism (the company), which means that despite their different contributions, it’s nonsense to analyze them as individual parts.
Marketers alone have probably nothing to market.
Engineers alone might have difficulties to market their creations (we all know exceptions though).
When they work together instead, they complement their skills and create way more value than they could possibly create working alone.
The bottom line is that "who is more important between marketers and engineers?", is a very stupid question whose answer isn’t accurate and useful to anyone.
It’s the same thing as trying to figure out who is the most important brother/sister.
Siblings are a team and in a team (especially in your company) there is no such thing as "more important than..".
Don’t waste your time with this question and make sure nobody in your team waste it too.