League of Legends (LoL) Question: Udyrs Tiger Stance

1. "Dealing physical damage to an enemy champion reduces their armor by 5% for 4 seconds." - Black Cleaver. So yeah, each tick gives 1 Black Cleaver stack. How much ticks there are in total, I honestly do not know. I searched wiki and everything, couldn't find an answer, so you either have to test it, or you can assume that it is 1 tick per second (thus 2 ticks in total)
2. Udyr is based on auto attacks, which means he needs to remain stuck to the enemy champions in order to be useful, thus he needs his movement speed. You WILL need 5 points in bear because of that. Turtle is also necessary since you have to remain close to the enemy thus will take a lot of hits. So, since the other 2 are damage options, you can easier pick one over the other. I'd say if you build more AS, get Phoenix, if you get more flat AD, get Tiger.

All the information given in this answer is done by logical analysis and research. I myself do NOT play a lot of Udyr, so I might be wrong here and there.

here is a guide to toplane udyr.
1.idk
2.as toplane udyr, don!t level up phoenix at all. forgot about the rest, check the guide ;)
3. there is no 3. so why do i even write this?