If you want to revive strategus, you need to firstly bring randoms and singles players from c-rpg on strategus and make strategus interesting for them. Secondly, make dat randoms profitable for fractions.
I would like to see on strat private ownership and buildings players in faction's fiefs, which would give a bonus to the experience or income c-rpg gold for the player and the bonus for the faction itself.
Add diplomacy system, where I as the leader of the faction may add allied faction and the faction of mercenaries.
Add a road on the map (straight line connecting the neighboring fief in a straight line) to increase the speed of movement of the armies of x5 x10 x20 rest of movement off road nerf to 0.5 0.2 0.1.
Fights. Change the system of strategic battles, making them more arcade and fast. Now loosing 1-2 armies leads to that the whole fraction leave strat with tears in his eyes. Boost experience bonus on EU3.
After the attack, the battle is query for fighting eu3 an hour (time for reinforcements). Then the battle begins. server automatically distributes players on the teams according to the diplomacy. A team the factions players + allies, team B all who is not in the diplomatic list. After the battle starts next, etc. nonstop.