1) If you had the slightest knowledge of nutrition you knew where to look up the amounts of protein these two plant ingredients contain. I shouldn't have to provide you with any science since it's public knowledge available in plain sight on the net.
2) Beet pulp as used in dog food is a source of dietary fiber and does not contain any sugar, nor is a filler. A filler is an ingredient who serves no purpose what-so-ever. Do you understand what a dietary fiber is? Beet pulp is partly fermentable vegetable fiber and is a source of food for existing bacteria in the gut. These desirable bacteria colonies need stuff to eat and that is exactly what beet pulp provides. Beet pulp (and other sources of dietary fiber) is an essential part of good digestion and enhance growth of beneficial bacteria. Google it. I'll provide links as soon as I say something remotely controversial.
I disagree on two points you made.
1. Beet pulp does not contain "no sugar". It contains less sugar than Beets themselves, which are high in sugar.
2. Beet pulp is absolutely not essential to good digestion. I don't eat it and my dogs don't eat it and we have iron stomachs.