PRIORITY LISTS: An Often Unmentioned Disclaimer
There's a near impossible number of combinations of troops, levels, Generals assigned(both sides), general in march, active boosts(both sides), research (both sides), etc to have a 100% accurate priority list. Even if you did, it'd take forever to read it, compare to a wall, and know exactly what to send. A majority of fighters have experience using their troops and can typically guess priority. But they aren't always right.
The lists are guides to get you going in the right direction. They are immensely helpful to many and can certainly be accurate in many instances, and I absolutely give thanks and props to those that take the time to create them. However, things will not always go to that script. Every wall can, and usually will, be different. Understanding why is very difficult. Many times where a troop is clearly drawn to attack another troop, the explanation is simply that it is, you can see it, but can't exactly explain it. Which is pretty much how these priority lists are formulated.
There may be a formula that certain troops use to determine priority, or dozens of formulas. I'd like to think Kabam at least has a mathematical rhyme or reason for why a SSD with 200 melee attack will go after a 10000 life MH. But alas, I've learned to accept that they do. This is why many, including myself, will suggest that you test troops small batch before committing a large march.