Which of course entails even more subjectivity. As it stands, it is not worms or whales that write textbook evolution and attempt to document it as a progression from the simple to the more complex, sort of like this . . .
Now, maybe you don't believe evolution has anything to do with arguments from the simple to the more complex. Perhaps you should give certain members of your choir a talking to.
So your argument is that a horse (Tertiary) is more complex than a shark (Devonian)? Based on what?