Yes and no. I guess pokémon of the same type may gel better with each other, but that doesn't mean they'll all necessarily get along. After all, it's not like we only befriend other humans, either - some humans are real jackasses.

[While Enenra chats with Mecchan and Hina, Hinobuta gets distracted by the smell wafting over from the food stalls, and after sniffing for a little while, it comes over to Hijikata, grunts and points.]

Human food isn't good for you, Hinobuta, you know that!

[When the big pig pokémon makes pleading eyes, he caves in almost immediately.]

Okay, alright. I'll treat everyone! I guess Enenra can inhale the grill gas.