Now im seeing a lot of people run Totto'Eko in the army list forum and i want to understand the attraction and benefit, because to me he looks overpriced. The model is awesome though.
Vanguard ability, access to all Heavens spells(underrated lore imo), re-rolling 1s is a huge boost to any magic phase but especially a Slann.
You've got a skink priest lvl 2 (50 slaves) Then loremaster (17.5 slaves) Then vanguard D3 units that does not normally have vanguard (5-15 slaves slaves? (likely 10 or more)) Rerolling one's in magic, 1/6th of incidents rerolling 6's, which while painfull does stop miscasts. (7.5 slaves) rerolling the comet (2.5 slaves) 5 + Ward save (17.5 slaves) palanquin special rule - and ability to guard in skink cohrt's second rank (5 slaves). I might have forgotten something, but that there alone comes to a total of 110 slaves - that's 12.5 more than we're paying for him. Several of his abilities are hard to put a Price tag on, but nonetheless quite crucial in a game - the vanguard rule, and the rerolling one's in particular, the comet is also slightly hard to but a tag on, but we know what a 5+ Ward costs, we also know what we pay for a loremaster of high magic, and i am assuming the same should be true for heavens. You're getting more than you're bargaining for, Tetto can/should be able to turn a game around on presence alone. The vanguard ability especially is golden. The ability to re-deploy 1-3 units after deployment is golden.
I applaud your attempt to math this, but I think you may have undervalued rerolling the Comet and overvalued putting him in a cohort (balances out though). Vanguard is worth 15 Slaves (or 6 Cohort Skinks but no one likes to use that unit of measurement but me). Also there are two other aspects that increases his value slightly. 1) With Lore of Heavens you can stay back a ways and still cast all your spells 2) He comes out of hero points so you can still take a Slann or an Oldblood on a Carnosaur easily. There is another downsides. 1) he cannot caddy an arcane item 2) if you are addicted to lore master or WD Slann your power dice will be stretched tight. I consider this a plus because I am looking for an excuse to use more BRB Slann.
I did also mention it was hard to Price him, but i felt that attempting was the most "winning" argument when the OP Refers to him being overpriced, which i cannoy fathom. As with everything though, he needs to be in certain lists to Work, funny thing tho' is considering what lists he doesn't fit into is hard. Passive lists -> guaranteed comet to plant midfield while we wait for the enemy to advance and magic them up with our slann. Aggresive lists -> our carnos and monsters now have vanguard. Mid way lists -> mix between pushing around enemies with comet and vanguarding threats towards our enemy. I'm certain there's somewhere he doesn't fit - but in the used meta of Slann + TG w/ avoidance and nuisance spread pattern, Saurus Cav stars, and the increasingly popular Kroxigor units of 5+ i cannot see where he does not pull his load. Also a carnosaur fan such as myself should be using him simply to vanguard my Scar vet BSB on carnosaur
Tetto is by far the best and cost-efficient name character the lizardmen book have. Simply the D3 Vanguards are what can pay him in points. Say that is one turn less of enemy cannoning our troops. And while it is easy to keep him out of harms way due to lore of heavens (comet) he is a good buff mage as well, even though he is only a lvl 2 mage. Heavens buffs work well with saurus/cold ones. The ability not to take a dispel scroll bites though.
Lvl2 priest + 5+ ward and loremaster is 165pts. You pay 20pts for the rest. No need guess any numbers. He's quite cheap for what we get.
So you have sold me on cost efficency. Does he fundamentally alter how you use a cohort when he is placed in it? Can it be used for an Alter?
From my observation, the one thing Tetto SHOULDN'T do is deploy in the same army with a WD Slann or High Magic lore master. That's 13 spells. More if you take an expendable channel. Other than that, Tetto would work with almost anything. Large Cohorts, Temple Guard Slann bunkers, Carnosaurs, Salamanders, Razordons, Saurus Warriors and Kroxigor would all enjoy Vanguards. Most armies have one or more of those things. As Vamp Teddy wisely said, a defensive reactionary army would get lots of use out of Comets.
I haven't tried it yet, but I don't think you'd want Tet's bunker to do much fighting. I'd probably give him a bunker between 20 and 30 Skinks and hang back and cast spells.