PPH - Power Per Hour: This is the primary figure I base my army build queues around in the expectation that once all my Lost Arts and Building Upgrades are complete I should be able to maintain build queues around the clock.
PPU - Power Per Upkeep: Essentially how much power do I get for each unit of food consumed. The higher the value the more powerful army I can maintain. As I don't keep hold of an army for much beyond a week this figure has a lower priority. The less full your queues are the greater weight you should give to this value.
Archers - Slight weighting towards Infantry and Cavalry. Your first defensive unit, and will remain arguably your best defensive infantry unit for a long time.
Dwarfs - Heavy weighting towards Infantry and Cavalry. I fail to see the point of these units, their marginally higher ppu doesn't make up for their lower pph and low speed. Stick with Archers.
Lost Ones - Balanced weighting. The first units you can build with Maranian Amulets these are a great way to fill up your build queues. They will eventually be superseded by more powerful Maranian units but even then you may want to build these to even out your defence.
Huntresses - Balanced weighting. I do not have information on cost at this time so it makes it difficult to see where they fit. Slightly more powerful than Archers but their low pph puts them nearly at the level of dwarfs for long build queues.
Nomad - Weighted to Cavalry and Occult. Your first cavalry unit and one you should keep building for a long time. Great pph and ppu.
Barbarian - Weighted to Infantry and Cavalry. Equal in defence to the nomad unit but slower moving higher capacity. I'd build a mix of these and Nomads to give a defence better capable for a mix of attackers.
Reiter - Balanced weighing. The Maranian defensive cavalry and probably my favourite Maranian unit. The pph isn't great dipping below 400 but it's ppu compares favourably with Undead Dragons when you also consider the cost of building and it is likely to have a much higher level until deep into the game.
Golem - Weighted to Occult and Bestiary. Your first Occult unit and your best pph for defensive units. If you can keep a queue filled with Golems you'll be a happy player.
Demons - Heavy weight towards Occult and moderate towards Bestiary. Demons are marginally better ppu and slightly cheaper to build (adjusted cost per hour). I consider these a role filler, for those expecting attacks comprised solely of occult units.
Griffins - Weak against Infantry, Strong against Occult and Bestiary. Your only primary rss based defensive unit has a great pph and the best non-maranian ppu. Always keep some of these on hand.
Undead Dragons - Weak against Infantry, Strong against Occult and Bestiary. Your only Maranian Amulet based combat unit in the Bestiary group and has peerless ppu. You will struggle to resource the building of more than one per day.