Warmaster no!  Not at all a fan of fantasy part of the game. Never liked the Lord of the rings, elfs and ork and that wizard magic bullshit. Mostly I hate the idea around the mechanics of the magic/spells part in any game. I believe it takes away for the actual generalship of an army. It is a ramdomness outside of the fog of war, that does not support the fog of war concept.

Why Warmaster?

Space!  A standard 6x4ft table swallowed two 2000 point armies. That size table could have supported twice that number with plenty of room to maneuver.

Much larger table, but you get the idea.

Different system. Each individual 10mm dude is removable as a casualty .

Scale

         You have to like the recommend scale, 10mm. Very fast to paint, cheap, no assembly, well supported lines. The minis have just enough detail, you can represent the differences in arms.

         No need to spend days cleaning and putting together plastic. Plus a fortune in Little Big Man stickers. (With that said, the 28mm ancients are drop dead beautiful when painted. I am guilty of owning a ton of roman 28mm, mostly unpainted.)

         The speed at which 10mm can be painted. Yet when fielding the 28mm armies of an ancient battle, you could be painting for years just to get one side done. (It took me 4 plus months to do 3 units of Roman Aux. And they still are not based!) Then 2 to 3 year later you have 600 dudes fighting it out. I would never ever be able to maintain the focus of 3 years to paint one time period and not buy another project outside of that time period.

         Sadly doesn’t fit the picture I have in my mind. 30,000 romans fighting 60,000 barbarians, Those 600 miniatures would be on a 100 to 1 for the romans and 200 to 1 for the barbarians. A cohort, 480 guys, would be 5 dudes! With 10mm and a Warmaster frontage of 40mm, your exchanging 5 28mm dudes @125mm frontage for 48 10mm dudes on a 120mm frontage.  That is a 10 to 1 ratio.

Price

         Price wise 100 10mm old glory dudes are 3 bucks. 5 28mm Aventines are 8 bucks without shipping from the UK. Less than a 1/2. Now us poor folk with space limitations can have an ancient battle that looks like an ancient battle on a 6×4 foot table.

Building a player base

Warmaster is simpler.  
          Hail Caesar is almost a straight up copy of Warmaster. Biggest difference being Warmaster is set up for tourney play and Hail Caesar is not. Thereby making a new player feel less forced into historical outcomes and more so his own generalship earns the result.
          Fields of Glory is a more accurate representation. Movement in FoG is much more detailed, complicated. Where Warmaster is more abstract and not so deep in the weeds. I will be teaching the locals here how to play. The local love of war and history does not exist here.

In the end, Warmaster plays faster and is easier to learn.

         Hail Caesar and Field of Glory have far better army lists that represent the period and flavor of the nation states. Mainly because they were set up for historical, not point matched gaming. In the future I will steal heavily from both.