Currently testing some changes to the battles that I hope will improve the whole experience a bit.
For example I want cav to function more than just as the hammer (charging enemies in the back) and chasing routing enemies. Medium, heavy and superheavy cav should be fairly decent in prolonged hand to hand combat (unless versus spears/pikes).
At the same time I want swords, axes and maces to be slightly more effective against infantry in general - but that also means that players need to feel there's a point in recruiting spearmen for more than just anti-cavalry duty. Here I'm trying different new formations that will be unique to just spearmen (not hoplites, looking at slightly changing the hoplite phalanx bonuses too).
For example, supposedly most Roman players will field mostly gladius-infantry right now, with perhaps 2-4 spears at flanks. With the changes I'm experimenting with it will be more relevant to adapt to your enemies army composition than with the old balance.
Let's say I'm fighting the Macedonians and they have a bunch of heavy and shock cav. You'd want to bring more spear infantry with these changes, because even though gladius infantry will beat most other infantry in combat - they will have a harder time with heavy cav now due to the weapon not being optimal against horsemen. This means that cookie-cutter compositions for all types of enemies won't be as obvious any more.
There also needs to be a reason for the player to invest in more expensive spears instead of just buying the cheapest through a whole campaign. With the new changes heavy cav will destroy spear levies (albeit still taking extra losses due to the fact spears get a bonus against them). Charging a Nizagan spear levy with Cataphracts head on, the horsemen might lose a few soldiers but completely destroy the levies in the process. But try charging decent hoplites or elite spears with them and the results will be very different.
I'm my Parthian test-campaign (I'm playing with 41-units per army) I had around 30 nizagans in my army when fighting the Scytho-Sarmatian Horde (confederation), due to them having lots of cataphract-tier cavalry (post-reform). The ratio of 1:1 just doesn't work any more when it's a levy spear against a good melee/shock cav, so if you're going with cheap spears then get lots of extra!
You can see below how many men these poor levies lost and how many they've managed to kill so far.
Back to spear-specific formations, the plan is for all "cheap/basic" spears to have one basic formation - and for all elite spears to have the basic one and a second different one (or just the better one, but different from the basic one). But since the AI doesn't seem to be able to use just any formation, this might not be feasible. Time will tell!
TL;DR
The overhaul is still being worked on and there are lots of changes/new stuff I'm testing right now. I'm also waiting for the main DeI team to release the hotfixes they need to release, because it's a lot of work having to update the submod every time they release an update (even small ones will often mean lots of adaptation).