Stop Wolves From Becoming Angry Through Walls

In a custom Minecraft map I'm making, I have a pet shop where you can spend points you've earned on the main map levels to "adopt" pets. This includes horses, cats, and dogs. That's all fine. However, in another room nearby, but not adjacent to, the pet shop, I have a NoAI skeleton as decoration/signage for a minigame involving skeletons. Annoyingly, the untamed wolf in the pet shop (the one that you will tame when you adopt it) is becoming aggressive towards this NoAI skeleton, even through several walls and over 25 blocks away. I tried setting its Angry tag to 0b every tick, but that just makes him flash between hostile and passive on and off each tick.

How can I stop him from noticing the skeleton if he can see through walls? Or at least, can I stop him from becoming angry at this particular skeleton?

Mobs that are on the same scoreboard team will no longer be aggressive to one another. This includes wolves attacking skeletons, zombies attacking villagers, hostile mobs attacking players, etc.

/scoreboard teams add Friendly

/scoreboard teams join Friendly @e[type=Wolf] @e[type=Skeleton]