There are big 3 things mixed up here.
1 straight vs lateral. zhi jin dui heng jin.
If the opponent uses straight energy, we use lateral one to neutralize it.
If the opponent uses lateral energy, we use straight one to neutralize it.
It is like a spear vs a shield. Back and forth.
2 rising vs sinking (up and down) energy
Downward energy is more important than rising one.
3 expanding vs shrinking (exploding vs imploding) energy
Peng is upward, forward, downward and expanding energy.
Huan yuan is a mixture of all of the above. It is circular and centering around dan tian. It is exploding and imploding.
Meaning we have to practice one energy at a time.
Then we mix 2, then 3 then all.
There.