Yeah, I've played with Woljif as a straight ET a couple of times; he's extremely effective. Also multi-clessed him with Vivi (both as a 12/8 and a 3/17 spilt) and yes, he is strong (unless you get ambushed on the overland map by a pack of plagued smilodons and you can't get his buffs up in time).
Again, I wanted to experiment with him and so far, I've had zero problems running him as a ET/EA.
Bottom line is that for better or for worse it looks like the intended play pattern is to get replayability/variety via different group make-ups and different options within the starting classes (and there are a ton, especially with Second Mystery/Spirit on Daeran/Cam) instead of multi-classing like you can do productively on some companions in P:K. Maybe because they saw how badly people butchered things in P:K with 3.5-style dipping and splashing and were trying to nudge them in the PF direction of getting that same effect from leveling within one hybrid class.
Here are some of the options within the starting classes I've found:
Seelah:
Divine Weapon Bond vs Mount: Mount probably just flat-out better but Horse is awkward in many areas. Divine Bond very good since min/lvl, can be use for Barrage etc, uses her Shield Focus better since she gets attacked more.
Mythic Spell Focus Evocation vs combat Feats: great with Archons, Holy Whisper is awkward since not many (other) Good melee companions and Crusader's Edge already applies Sicken, Resounding Blow very good tho.
Shield Bash vs Intimidation Feats: many great Bashing Shields and takes better advantage of Smite Bonuses but takes most of your Feats, works well with Balanced Defender Sword (gives +3 to Bash), other CHR-based companions can Intimidate, eventually get Frightful Aspect
Mythic Improved Initiative helps get Mark down faster for rest of team vs Mythic two-weapon or Spell Focus, Abundant Casting vs Last Stand etc...
Lann:
Can multiclass well P:K style
Cam:
Melee vs Ranged
Caster focus (she gets good late spells including Stinking Cloud at lvl 5 and/or can meta Snowball with Second Mystery Frost and Secret Hex for meta and even go Winter Witch - very good vs Devarra and high AC/SR foes) vs melee Focus (effective tank, especially with both False Lifes and Thorn Body, Ghost Touch and Bane Weapon)
A lot of ways to go with Hexes including prereq for Shatter
Ember:
Infinite options (kind of the point of her class)
Conj (bypasses SR) with Summoning, Necro Rays with Reach Rod Curse + Hexes, Cackle, Burn ok but not great because Meta makes Spontaneous Full Action, Bow (she's an Elf) + Transformation, Enchantment (her unique spell is Enchantment)
Sosiel:
Combat Focus with Self-buffs (including great Domain abilities with Domain Zealot)
Evo nuker with Mythic Focus (makes Archon's better, Holy Smite always on, easy Meta with Favorite Meta)
Abjurer with Mythic Focus Abjuration for Banish/Dismissal (plenty of targets) and Dispel, Greater
Necro Touch spells
Daeran:
Mounted with Second Mystery Nature (helps overcome his drawback, a lot of work to make him viable in melee but gets there eventually, can choose Wolf which is easier to maneuver but bad with Frightful Aspect)
Ancestral Mystery buffer Evo nuker (sets up with for Unholy Stormbolts using Blackwater Gauntlets and Max Unholy Rod)
Battle Mystery melee with Divine self-buffs
Bones mystery Necro?
Wolj:
Transmuter for Swift Slow/Obsidian Flow
Evo nuker from straight ES to get to Hellfire (pick up Favorite Meta along the way)
Underhanded Trick with True Strike
Aru:
Xbow crit fisher vs Longbow Enlarged
Instant Enemy spammer vs buffer
Instill Vigor + Stone Call, she can even beat saves with high CHR if your want to try to get there with Entangle + ranged team, Life Blast good vs Undead
Snap Shot Tripper with Aspect of Wolf
That's off the top of my head. I'm sure there are others. A lot depends on what MC is doing.