Erm...
Well, close you guys. Growlithe would actually be going first.
Also, if you guys are the trainers, your Pokemon are controlled by me. aka NPCs.
Also, I'll use your combat as an example.
Machop uses Low Kick.
Then, Growlithe dodges.
Then I say the results of the dodge and the kick, and then it is Growlithe's turn to attack.
There we go. Now I would make my analysis.
Growlithe spits the embers out at high speeds, and Machop just barely avoids with that tremendous leap! An ember nicks his leg, for 2 damage.
Pokemon all have a health total of 30, no matter what.
Machop's health is now 28.
Machop to Attack, Growlithe to Defend