but I just can’t reach the soulsucker’s village because the goatfolk just keep killing me on my way.

Mamon Souldrinker can be, IMHO, a hard fight, the quest isn't a prerequisite for anything, and the rewards aren't anything fantastic. His fight is a quite significant bump in difficulty from regular goatfolk, I'd say. I'd probably back-burner it.

• At least for me

I normally play a melee character

and I assume most people, the biggest problem with the goatfolk is the goatfolk sowers, which have explosive missile weapons. You're in a jungle. Use the trees to break line of sight with them so that you only engage them in melee. Don't engage crowds if you aren't up to it; you can lure lone enemies off onto an adjacent, cleared screen. If you're a melee character, and can't use trees to get as close as possible, Charge will let you close the last bit of distance quickly.

• Discretion is the better part of valor. If it looks risky, don't take the fight.

• When you walk off the current screen to another, enemies who are close to you will follow shortly thereafter. However, if you leave that screen before they enter, you won't be followed (e.g. leave near a a corner of the current screen, then exit off to another screen prior to the enemies following you to the second screen).

• You have a Sprint ability in your abilities tab. That'll let you briefly move faster than enemies. "Sprint adds the ability to start sprinting, with a cooldown of 100. While sprinting, a character's movement speed is doubled, and this effect lasts for 10 turns by default." That'll help break line-of-sight or get off the current screen.

• Especially if you're a mutant, you may have some "escape key" abilities already

most roguelikes tend to favor having some kind of "escape key". For physical mutations, something like Phasing, or the ability to emit line-of-sight blocking gas (Sleep Gas Generation, Corrosive Gas Generation) for physical mutations. I don't play espers much, but for them, maybe something like Force Bubble.