Shadowy alliance

I'm considering purchasing mandrakes. There, I said it. Before everyone tries to talk me down from this particular ledge, some context - mandrakes are our only infiltrating unit, the models are (in my opinion) stunning and unique, and their shooting is actually pretty good. Their biggest drawback is the need to get a pain token on them straight away to make them useful though. But not to get distracted by this, what if they were with someone who could help them get a pain token on the charge? In this age of alliances, this gives us the option to ally in Karandras. Yes, he's expensive, but is actually good at what he does. He would make the mandrakes fearless, has six strength 8 AP2 attacks on the charge, tanks wounds for the rest of the squad or passes them off onto his invulnerable friends, and can infiltrate with them (the only character able to do so).

This unit does in fact have potentially more survivability than putting Karandras with Striking Scorpions, as the bulk of the unit gets a save against everything rather than being whittled down by AP3 or better fire as well as still having stealth. After Karandras has helped them amass pain tokens, he can happily split off, leaving any pain tokens with them as he is not allowed to take them. Then you have a unit of 5++, 5+ FNP, stealth packing models, with a pinning shooting attack (rare for us) and strength five on the charge (potentially). They could even be fearless if you leave them together for a while and slingshot yourself into plenty of fights, although that would require wiping out a unit a turn for three turns in a row. And Karandras is still wandering about, both of them in your opponents backfield. If you've got Striking Scorpions too (like I have) there's another Scorpion's Claw milling around too.

Yes, this will only be really effective against certain armies, but isn't that the way with a lot of things? What do people think to the viability of this plan?

On the plus side, this is probably the most effective means of using Mandrakes I've seen in 5th or 6th editions. On the negative side, that's not saying much!  

I actually quite like it but it is pretty expensive and very situational. Would be interested to see how it works.

It is very expensive, especially for something that isn't a true deathstar unit. But it does have excellent staying power. Once I get the necessary bits, I shall report back on how it performs  I see them being excellent at applying first turn pressure, as well as denying enemy infiltrators, but we shall see!

Whatever the results, please lie and say the are amazing. I'll go along with it and maybe I can fool my brain and wallet just long enough to get a few boxes lol