The lack of indie mages is difficult. While no indie games are not uncommon I don't recall seeing any that also removed magic sites that allowed unit recruitment. The idea was to really emphasize national units and encourage getting opponents' caps to diversify your magic and troops.
Based on the previous games it's tough to say if a certain type of build is best. Nations have done well with SCs, good scales and bless (though perhaps to a lesser degree on the latter). Without any indies you also have to consider how you'll get access to paths like nature that you'd commonly get from indies (assuming of course your national mages don't have that path) so filling in the gaps in your nation's magic paths is obviously important as well. Some paths are also just difficult to break into with summons. There actually aren't any summons with air magic. Astral depends on getting the right randoms on either hidden in sand or spectres.
This is definitely an experimental game and I can't make any promises as to balance. Hopefully it will be fun, though.
