Honestly, the only thing I can think to do with Lemuria is spam consuls everywhere. They're basically research-0 wraith lords with H3 instead of D3, with everything that entails. Demolish your scales to take a strong (Tri, maybe even quad, though iirc a quad would put off your first consul a handful of turns due to needing to empower something) bless and put those guys out more or less every chance you get. You're pretty much the only nation in the game that can have basically spam an end-game SC chassis by around turn two, and with a good bless those consuls can solo almost any indie province in the game without research or kit -- just a scripted bless, unholy power, holy avenger, and it's off the races. (E2: And with enemy armies? Just bring two or three together and watch as they do hilariously terrible things unto your foe's cloaca.) They are absolutely ridiculously, border-line farcically, strong for their research and gem cost.
As for the reanimation chaff, the closest thing to a trick with them is "Go underwater". Amusingly, the UW shadow soldiers are marginally stronger than the land ones.
Arguably, the real idea is to play lemuria as a disciple, alongside one of the forgier nations (and a god that probably goes a simple N/minor E bless -- it's all the consuls really need, though more helps. Actually, they almost don't need a bless at all but... it helps.), and basically do nothing but produce consuls for the other nations to equip. Use the whole no-domkill thing to nab up indie mages for research and eventually your own kitting and fill the world with immortal, self-blessing, discounted wraith lords. Just... think on that for a little while. Eventually you might translate into using those immortal battlemages alongside the immortal consuls and make any attack into your team's dominion just the most absolutely goddamn miserable thing ever.
E: And yeah, they're astral/death. Tops out at 3S or 4D on 1/4th of the grand lemurs, which are entirely too freaking expensive but 1/4th of them are teleporting immortals right out the gate. So, y'know, you can do things with that. They're also stealthy H3 units, which... you can do things with, since your basically everything (well, everything reanimated, and that's going to be quite a lot after a while) in regards to chaff is also stealthy. It's one thing to not be worried about lemur's chaff because you've got priests or whatever, it's another for 2-300 of them backed by a pretty killer battlemage to just randomly show up anywhere in your nation while you're desperately trying to stave off the infinite march of the consuls.
E3: Really, it's just kinda'... okay, pop quiz. Turn 3, lemuria gets their first consul. Every other turn thereafter, another appears. It's turn 15. There's a half dozen might-as-well-be-wraith-lords rampaging towards your nation. What do you do?