Farrow Shaman 5E tactics

Like many Iron Kingdoms monsters, there's a reasonably close correlate to this critter in the 5E Monster Manual that Keith Amman has therefore already covered in some detail - I'll be using Keith's analysis as a basis, noting differences where relevant.

Farrow Shaman example

The farrow equivalent of the gatorman bokor is in fact more like a druid than a priest, although lacks the shapechanging abilities usually associated with that particular class. Apart from a higher WIS 16 (slightly higher than the NPC), they have an identical ability contour as their regular cousins, making them a support caster in terms of role. This makes them savvy enough to only fight if they think they can win and choose conflict carefully, avoiding if there is an advantage to parlay. The only other major differences are lower AC 11 (without barkskin), an extra 3 HIt Dice, and the addition of proficiency with Medicine. They retain proficiency in Perception and Survival, as well as a farrow's Keen Smell.

Comparing to Keith's analysis of the druid NPC seems valid, as there are really only some other minor differences - the totemic polearm is mechanically the same as a quarterstaff (and can be similarly affected by the shillelagh cantrip) albeit with a +3 rather than a +2 bonus from the higher WIS score.

Even their spellcasting is very similar, so let's look at the differences initially:

• Spike growth is far more useful than animal messenger, requiring concentration but inflicting damage without a save, albeit with a WIS save opportunity to recognise the danger. It's a game-changer, particularly given its long range of 150 ft.
• Likewise, fog cloud is a better combat option than speak with animals, but as it's also a concentration spell, it is either cast on the shaman's opponents at the start of battle or more likely reserved to cover the farrow band's flight or if the shaman loses concentration and another spike growth is not needed. If overcast as a 2nd level spell, the radius of the fog is 40 ft., not just 20 ft - it can be coupled with longstrider to effect an escape. The main issue is the heavy obscurement causes enemies trapped within it to be blinded, but also anyone targeting opponents within the cloud has disadvantage to attacks.
• Arguably poison spray is less versatile than produce flame and a DEX save halves the higher damage potential but it is well aligned with the venomous theme.

So how does all that change the base tactics Keith presents for a druid or a lizardfolk shaman? 

Quite a bit actually, as firstly there are now several concentration spell battlefield control options: the base entangle, plus fog cloud and spike growth. Of the three, spike growth is the most damaging and does not require a save (damage is automatic if a creature moves through at normal movement), although both it and entangle lose some benefit in areas of pre-existing difficult terrain like a swamp. 

It's really going to depend on whether the farrow band ambushes the party, begins with a peaceful negotiation that turns sour, or is surprised by the player party. So, I'm going to disagree with Keith here and propose that a well-placed spike growth (or perhaps entangle against low DEX creatures) is going to help the band more in the first situation, whereas fog cloud allows the band to either regroup or retreat as required for tactical advantage. It has to be placed well to not affect allies but used correctly to help the shaman control the battlefield.

Once one of these concentration spells is cast, the farrow shaman can default to the standard druid melee tactic, but particularly if opponents are slowed by spike growth, there may actually be a benefit to casting barkskin in preparation (if not already before to parlay or expected battle) while opponents try and circle around into melee - the creature lacks any ranged spell attacks, so unless given a firearm such as a pig iron (pictured in the default illustration above, see the original farrow post for details) it really has nothing to do but wait until an opponent closes, continue to maneuver to a better position or flee. 

The addition of poison spray alters the weapon used for melee, but the tactics remain the same as a druid - hit with its chosen weapon (poison spray does the same average damage as a shillelagh empowered totemic polearm but forces a CON save rather than requiring the sham to hit), reserving thunderwave for if it is surrounded by 3 opponents or more.

If the battle turns against the farrow (reduced to half the band's numbers), they seek to flee similarly under cover of fog cloud, using longstrider to put more distance between them and their opponents.

Farrow Warbands led by a Shaman 

Warbands led by a farrow shaman are different from those led by a warlord, most notably smaller. Given the shaman's higher WIS score, they are more likely to parlay and offer to trade than to attack. They may prefer to engage at near range and are more likely to flee if they are caught in a battle going badly as the shaman's powers lend themselves more to defensive strength, unlike the Hog Wild induced frenzy triggered by a farrow warlord. 

Note: a shaman in the same band as a warlord is an interesting mix, with the shaman potentially mitigating the war leader's aggressiveness. In combat, Hog Wild should probably apply to any farrow *melee* weapon attack, including the shaman's totemic polearm and grant the spellcaster the extra attack (in addition to its default poison spray attempt). Synergising the defensive AoE spells with a warlord's minions tendency to move into melee may require some juggling, but it's likely a shaman's influence will be reduced once the battle is joined.