You did get lucky.
I have kinda an odd tank situation going on with a gsp.
I made a mistake of buying it without researching first. I was still very new to tropicals at the time. I thought it was a fully freshwater puffer.
It's been living in a community setting for about 9+months. He's an awesome little guy and has only had issues with plecos. It killed one, but when I bought two at the same time that spread the aggression out enough that both managed to thrive even with a nip here and there.
Fahakas seem so lovable. If I can ever get an appropriate size tank I'd love one. Yours is adorable