When a goat has the weakness/strength potion effects, the damage they do does not change even if they are given effects that alters the damage they would dealt to the targeted mob. This also applies to summoned goats with the attack attribute set to a different value.

To reproduce

1. Go to survival
2. Use the given command:

    /summon minecraft:goat ~ ~ ~ {Brain: {memories: {"minecraft:ram_cooldown_ticks": {value: 10}}},Attributes:[{Base:0.0d,Name:"generic.attack_damage"}]} 

3. Let it ram at you
   → The goat deals damage even if the base value is set to 0.0
4. Splash weakness/strength on a goat
5. Let it ram at you
   → The goat's attack damage is not increased/decreased by the potion effect it was given.