[fantasma]

Regarding Marverni against small elite armies:

Marverni has - besides slingers - cheap javelin throwers. There is the spell farstrike at zero research for druids and early thaumaturgy research has good anti elite spells, I think.

The best bet Marverni has is to come out with fast expansion and lots of gold and diplomacy to demonstrate that you will make the attacker pay hard for an early attack. If you have to dedicate mages to counter rushes you have partly lost already, but the attacker will not get far either.

I would rate Marverni as 3 4 4 but very difficult to learn.
What you field with what orders depends so much on the opposition. You have to learn communions to be effective. You need to research extremely fast, building lots of forts.
It's endgame really depends on what you do about SCs. Your only thug is the golem.