I've done a rewrite of the rules for Ground War in Battlefleet Koronus, which I found disappointing. These rules are located at: docs.google.com/document/d/1ItRtCwMpMc3xkbzwcVQDuWEkZZ5oRIu96IQMhI8w9NI/edit

I hoped to achieve the following with these rules changes:
Scaling damage, as I felt that the scaling in the book was inadequate. I've added a Righteous Fury rule to create the small chance that a bunch of peasants overcome an elite tank army, but certain chances will be very small.
A consistent approach to cost/benefit, where every -10 Acq is worth somewhere near 3 Power (All subject to my own interpretation of "worth"). This includes set sizes for the armies, where Unit Strength is an abstract, representing different amount of soldiers/vehicles depending on Type.
Reduced timescale, to both shrink the battlefield (by making movement much smaller) and return higher losses. Note that this means that both orbital bombardment and artillery needed to be toned down, or they would totally dominate the battlefield.

I would much appreciate any feedback or further ideas!

Downloaded them and I'm going to print them out. I plan to do some 'what if' scenarios as a way to kill time for early arrivals to my RT game and doing things like ship combat and wars should be very useful.

Though I'm no wizard when it comes to analysis like this we'll see what turns up.

Well I too found the mass combat rules highly disappointing. As written, 100 men can, all other things being equal, inflict the same damage as 3000 men, That is just plain wrong.

I will try your rules out at the first opportunity and report back!

Upon first glance I think they are very well done. I will play test these with my group and give you some feedback once that's complete. As for your comments on titans, I think they should be a separate category altogether. In the BFK book, it lists 1 titan as having that kind of stat, but I disagree, if anything a formation/maniple would have that kind of stat. A single titan is powerful yes, but not enough to take on 1000 troops alone for example. Standard formation for scout titans would be 2 warhounds, battle formations are 3 reavers or 3 warlods. The Imperator is the only unit that I can see as having a stat by itself. Ordinatus and Praetorians too.

I'll download your rules and give them a trial battle, but thoughts on the titans:

The good, old days of Final Liberation. Titans were given the size of a company i believe, which was ofc more powerful than a tank company. But that is about the Power lvl I would personally hand out to such a weapon system.

Taking a Reaver Titan is a single unit for comparison, we get 3 individual weapon systems mounted on such a unit, with each weapon system being the rough equivalent of a whole tank platoon. 3 Leman Russ Battle tanks firing their cannons (plus the piddly Heavy bolters) should more than equal the firepower of a single plasma blastgun firing in quick succession. Personally i would rate the Warlord as being comparable to a tank company of 10+ Leman Russ. Reavers would be less powerfull and Warhounds were be deployed in doubles, being moderately more powerful than a single reaver.

Imperator titans would be VERY, VERY rare. Id let them have a more stratetic effect, since losing such a (pretty much) irreplacable asset would be a sad day indeed, i beleive most Legio do not even have such a titan.

In response to the post concerning the deployment numbers, id also never let a titan appear alone on the battlefield, unless the RT group has made said arrangements (needing pretty much a whole endeavor just to get ahold of such an alliance with a Legio). Id even go so far and say that its harder to aquire the help of a Titan than the help of a Space Marine company. Depending on the circumstances. Space Marines need overlapping goals, the AdMech might just give you a Titan for alot of resources (Archeotech or huge amounts of adamantium delivered straight to the Lathes) but unless a forge world is threatened they wont care. Plus the titans defending said forgeworld would be under direct AdMech control anyway.

But back to me checking your set of rules, and already a thank you for the work you put into it . Being a 40k tabletop enthusiast, i took one look at those mass combat rules and went directly MEH at them.