Half banana is right in that the complexity of DNA is not the starting point.
Hell, not even belief in God or the Bible is the starting point. Christians all believe in God and the Bible, yet the majority of denominations officially accept that evolution is a fact.
There is something else that is the 'starting point': Watchtower doctrine.
Watchtower insists that many of the tales in the Bible must be literally true, accurate accounts of real historic events. This includes the creation of Adam and Eve, and Noah's rainy days. Why? They claim because that's what the Bible says, but in reality it's because that's just Watchtower's very literal interpretation. There are plenty people who read these tales and see them and allegories or warnings in symbolic language.
Evolution must be rejected because it doesn't fit Watchtower doctrine.
Otherwise they would have no problem accepting it.
At first they claimed all life was created max 49.000 years ago (7 creation days of 7000 years each). That idea is clearly contradicted by all available evidence, and since the age of plants and animals is not critical to Watchtower doctrine they had no issue changing their doctrine on that point (although they did so very slowly and obscured to not scare away the oldtimers)
It wouldn't even surprise me that if Watchtower exists another 100 years, there'll be new lite and they manage to weave the fact of evolution into their doctrine too.
It should be noted that JW (and other creationists) either out of ignorance or on purpose mix up evolution and abiogenesis when augmenting against it.
As if an all mighty God could not have created life and given it the capability to evolve.
Another thing is that there's a fair amount of circular reasoning involved in JW (and others) rejecting reality. Any flowchart should show the circular reasoning too.
The Bible is true because it is God's perfect word. How do we know? Because it says so in the Bible.
In fact the whole system of belief is an intricate web of interconnected assumptions that often lead back to each other.
(literal) Creationists believe what they believe because they started with 'God created the heavens and the Earth, animals after their kinds, and Adam and Eve from dust' instead of asking 'what does the evidence show about life?'
Any argument they present against evolution is not in an attempt to find evidence of what actually happened, but an attempt to justify their religious beliefs.
A flowchart should reflect that. DNA doesn't really matter, nor does any other perceived evidence against evolution.
The starting point is belief in God and a literal interpretation of the Bible, without giving any place to physical evidence.