"Why is Superfeline so high? He's way too difficult to boost."
It's true that he is extremely inpractical to use for most players, however if you were able to max him out to +90, he is very strong against Relics across UL and notable for being required for Babies First for a casual play through and Revival of Origin 3 crown.
"How is Axe Cat not the worst Normal?"
Dark isn't as useless as you'd think. He wields a Medium weaken duration up with Dark Lazer, allowing many weaken units to reach 100% uptime which notably includes Professor Cat Jobs who needs this combo to cheese levels like Primeval Cyclone. But even as a unit, he has 2 notable stages being Hannya Revenge and Doremi Revenge where he can be used viably as a melee attacker.
"On the Crazed list, Crazed Cow is super high while Cow here is very low. This is contradictory, what is the logic?"
Crazed Cow ranked high because of his convenience in farming and rushing easier stages. Normal Cow has the same qualities except he is confined to early game content, as he becomes completely outclassed by his Crazed variant the moment it's unlocked. Knowing this, Cow loses all of his usage as the Crazed variant does significantly better with high speed and area attacks. Rarely do you use both together except for niche stages like Love Metal Hippoe.
"Why is Island Cat so high? He's slow, expensive, and his Red niche is overshadowed by Courier and Roe."
It is true that as a unit, Island is not a good pick especially in later game content. However, I have given Island lots of credit due to his dominance in Normal restriction stages. There are 3 notable stages: Wahwah, Hannya Revenge, and Doremi Revenge. Island is a top pick on all 3 of these stages which gives him a significant advantage over many other Normals.
"If you're running with the above logic, then why isn't Titan higher? He is strong on Normal restriction stages too."
Of the 3 Normal restriction stages, Titan is strong on Wahwah and Doremi. However, the placement before, Dark, is also strong on 2 of 3 Normal restriction stages being Hannya and Doremi. The difference is Dark has a weaken combo while Titan has some small usage as a unit like on Crazed/ Manic Bird.
"Why is Bird higher than Cat?"
These 2 units offer value at completely different points of the game. Cat is valuable as one of your primary meatshields for the entire early game (alongside Boogie and Tank) and only starts falling off once Crazed Cat and Crazed Tank are acquired. On the other end, Bird is useless nearly everywhere (including EOC) but has small usage against Crazed/ Manic Cow, Doremi Revenge, and has a research combo. Cat has more versatility, but Bird directly targets more relevant stages. I prefer the latter option.