Then ambush would be strictly better. When calling for changes please consider if your changes would make one of the options worthless.

Shock doesn't have "priority" over ambush, it just has the exact thing you need in that situation. All that ambush does is striking first, so if it manages to kill, the attacking unit can't strike back. Shock negates all incoming damage while attacking. The ambushing unit still strikes first but all of it's first-striking damage is prevented, so the shock unit deals it's damage. Both are working as intended. And it's still balanced since ambush works every turn (provided it survives) while shock works exactly once.
Don't see a problem here.

Originally posted by Bmx Bandit:

Both effect should cancel, it's dumb that shock has priority over ambush

no