I have been thinking about something similar, although using a buffmander and stealth cadre to get a pretty crazy lychstar.
My list idea was:
Crons:
Tau:
This way so long as your star is within 24" of the Tau it always has Hit & Run and stealth, while also choosing either counter-attack, furious charge or tank hunter depending on the situation. Also has a 2+/4++ Zandrekh with a 4 up reanimate rerolling 1's, while hoping Orikan becomes Super Sayian early as possible. Scary

The Night Scythe gets it into
CC ASAP as they are quite immobile. The tomb blades are just objective capturer's/campers. This means my opponent has to either focus the star or the tau, either way there should be alot of hurt being laid down.
I have literally no idea what to kit out the Tua with, I am completely at a loss and could have completely missed the mark with their firepower. At the moment its just sort of a wishlist as I am focusing on getting my cron's painted up (have alot to get through). Imma gonna see what my buddies think, one play's Tau so next time I catch up with him I'm going to pick his brain as to the legitimacy of this strategy/which units to swap out units for better ones.
Edit for improved list (battlescribe destroys any productivity I have at work lately

) and spelfing