I have always wondered what strategies could work with all factions, if any are out there.
You build forces then attack Tahts what works with me on very hard But i got a faulty game anyway
The economic strategies usually work for all civs. About military ones, spamming skirmishers and Men-at-Arms/Champions/etc. usually ends in victory, but it depends alot of your bonuses and the enemies bonuses, too.
Spam skirmishers, knights, and trebuchets. Then build the biggest possible force and attack. It always works.
I use combat squads of 4 swords men supported by 4 archers as the byzantines. In major attacks a groups of 40 work, usually 40 cataphracts supporting 80 swordsmen and 40 archers/skirmishers for additional support.
20 farmers, 15 lumberjacks, 10 dig gold, 5 dig stone. Others (150) are army (works on easiest, easy, and medium, on hard, its..well, hard )
heavy cavalry