I pushed through my Imperial guard game till the final quest arrived. Here’s a tip- if you play the Imperial Guard, turn off the quest line because it’s bullshit.
This game is remarkably similar to Warlock but I also find differences. Playing warlock, you could get by with fewer units; deploying them in multiple areas and spreading cities quickly in their wake. With Gladius I found that you need one major point of effort because combat is less brutal. Units can frequently take multiple hits before they retreat for repairs. You need a solid system of reinforcements and reserves to hold the line before reaching the tipping point where you either run away or break through and annihilate their weakened second line.
City spamming isn’t really an option either since they take so long to develop and don’t really offer much defensive benefit.
I’m looking forward to seeing if there’s much difference playing the other three factions.