The early stages of any game no matter what platform it was on was an important growth period for any guild. They would prioritise laying down a solid and stable foundation rather than going to war with another.
This was even more true for larger guilds. In a real war, if the commoners were affected or wiped out, then the warlords that controlled them wouldn't be able to expand either.
Even a large guild like Pure Lands could only pressure smallers guilds into joining their ranks to bolster their forces at this time in the game. They couldn't afford to offend any other major influences before they had a stable footing.
At this point, the Quan Zhen Sect's fame was equivalent to the midday sun. Although there weren't even ten of them, they were running amok in a city with a major guild like the Sanguine Alliance around and had even managed to force them to pay reparations! If he had a choice, Amitabha really didn't want to make an enemy out of them.