How do you upgrade units?

[Tyrax]

I've built the main archery range, but I can only recruit the low tier archers, how do you get the higher tier, like marksman?

[Lightning]

Decrees will upgrade them, if you choose wisely the option to have snipers is the one that makes them marksmen (archers)

[radziu93]

Your crusade has stats, similar to kingmakers' kingdom stats(as far as I know four of them). When Stat reaches treshold, advances to the next level, you get decree to pass about strenghtening council, then a day after your councilmans come to audience and you decide. Archers upgrade was on military or logistic council (don't remember, I got it while ago), but i wasn't first level, problably the third?

[Tyrax]

so I guess then I need to hunker down and wait until I get better units :D I can barely fight level 5-6 demon armies

[Lightning]

Yeah it makes it alot easier if you keep passing the decisions for upgrades later whenever you can

[Hightower]

Originally posted by Tyrax:

so I guess then I need to hunker down and wait until I get better units :D I can barely fight level 5-6 demon armies

The trick to success is to get the mage general with master of maneuvers. That will increase your army size/number of different units you can have in the army. After that, get cure wounds spell. That spell pluss clerics will keep your army alive. Archers are your best damage dealers. Those combined with damage spells will absolutly murder the enemy. I have not lost a single unit so far in the game.