I imagine nobody here likes math right? Not to list specific costs, but Kroxigor costs as much as 11 skinks. Ehh Ehh? So here's the problem, instead of adding the kroxigor to those 11 skinks, just add.... 11 more skinks! The kroxigor only kills 1.25 units on average, less if they have armor better then 4+. The skinks on the other hand kill nothing..... but what they CAN do is add +2 ranks and probably an outnumber, which helps your CR a lot more, and the unit is REALLY hard to panic, and REALLY hard to ignore, and if they absolutely have to they can fight with a unit of cavalry, and you'll have your full Command by virtue of the banner that's in the Cold one Riders, or like 10 saurus or something, whatever, go nuts.
Underwhelmed? It costs the same yo, and involves rolling less dice. Less dice = less chaos.
Less Chaos = the old one's plan. We're Lizardmen players, not Chaos, not Brettonians, not elves, our lives mean nothing, let the skinks die in droves, it's all part of the old one's plans anyway. Getting in character for your army is a major part of the game, you think I plan out complicated math when I play Orcs? Dot Kinna Grubbin' aron wit' da' 'umbers an fingz iz fur da 'ummies wit da big Shootaz,
un da boyz wit da flashy bestyz and da funny hatz. Gorra git me 'un o doze 'atz I sez to da' boss 'ut he sayz I'ze not flashy anuff fo' un o doze fingz. Stay in character for the lizardmen, plan things out, EXCESSIVELY, and especially abuse your higher understanding of maths. Your army is super reliable and tends to do what it's told, and if hypno toad is around the skinks won't run from much.
Sure your leadership goes down, and you still suck against fear, but honestly, unless the fear outnumbers you, or is actually terror, all it's gonna do is prevent you from charging or OH NO! make skinks hit on SIXES? Instead of what, 4's ? Fap Fap Fap, not gonna make a big difference. If you are supporting some beleaguered saurus or a stegadon or something you are gonna want those ranks and outnumber, getting outnumber is super important since it's essentially +2 CR, by taking away one of there's etc. etc.