Machines definitely play out differently from the other races. While you can build a 'fast' deck with the Machines they, IMO, play out best with a slower deployment and utilizing a lot of different unit types. I don't have a ton of time ATM but I'll throw out some points you may find useful.
1) Research is key, the Machines have a lot of great upgrades and weapons. Develop your area to the max and start cranking the tech.
2) Spiderbots. Take 5. I back them up with a couple Liches who I use to bushwhack enemy recon the Spiderbots find. Revenants are also good in this role.
2a) I never bother with the Ghost Probes - too easily discovered, less sturdy than Spiders and don't have Commando. My deep recon is all stealth hero based.
2b) Same goes for Hydras, though they can bushwhack light recon well they're not sturdy at all.
The idea here is to do aggressive recon in your area and progressively strip your enemies of their recon assets.
3) The Penetrator 1 point kill munition coupled with the Apparition and a handful of tactics equals dead enemy HQs once your heroes locate them. Nukes? Who needs 'em!
3a) If you can get into range, the Wraith is even better for this with Precision Strike and 1 extra attack and fate point.
3b) Also great for vaporizing enemy outposts when their stack is deep in your territory.
4) A Harpy with any of the Skeletors is great for early game exploration even without any recon ability.
5) Think combined arms with your armies. A couple of mechs or tanks with survivable infantry (Mk IIIs and Sentinels are the best but the other Skeletors get the job done) is deadly.
6) Nanite Cloud + Breakthrough(Proteus) = auto-breakthrough b/c the cloud always causes at least 2 dam. (did not come up with this but I forget who it was)
6a) For that matter, if you can crank them out, Nanite Clouds go great with every unit, even allowing Spiderbots a great chance to vaporize units they stumble over. It's the Mac Tac Nuke.
7) I have found Cyborgs, both types, and the Constructs only useful in theme decks.
8) As ever, Shock attack is THE MAN. So, Scourge Platoons, Zombie Launchers and Styxx's. But you only need 1 or 2 shock units per army really.
9) Don't overlook Thrall Chambers late game. I use them to garrison everything, do brute force recon, setup early warning lines and even for human wave assaults to soften up targets.
Hope this helps.