It shouldn't effect the marian reforms since the latifundia requires only minor city size, where as the city mod only puts restrictions on large & huge city size.
Other reforms are not dependent on city size.
These are the size limits:
HUGE CITY
Alexandreia - Delta Neilou
Terhazza - Eremos
Roma - Latium
Seleukeia - Mesopotamia
Persepolis - Persis
Antiocheia - Syria
Kart-Hadast - Zeugitana
LARGE CITY
Babylon - Babylonia
Arvernotorg - Gergovia
Athenai - Attike
Baktra - Baktria
Mastia - Bastetania
Capua - Campania
Camulosadae - Cassemorg
Taksashila - Gandhara
Sarmiszegethusa - Getia Koile
Armavir - Hayasdan
Memphis - Heptanomis
Sparte - Lakonike
Sardis - Lydia
Pella - Makedonia
Ekbatana - Media
Bibracte - Mrogaedu
Sinope - Paphlagonia
Swebotraustastamnoz - Swebolandam
Syracuse - Trinakrie
MINOR CITY
All other settlements can reach minor city level.
I believe this mod will affect the General's Bodyguard reform for most of the Hellenic cultures that is tied into the Vanilla March of Time event.
The March of Time event is triggered on the Romans building a Huge City in Italy (other than Roma).
Typically the first city to trigger this is Capua or Arretium but According to the list above, that appears impossible.
So yes, this mod does affect the Generals Bodyguard reform (it won't happen).
No, you're mistaken - the EB March of Time is triggered on the Romans building a Huge City in the Italy (INCLUDING Roma).
The wording (excluding Roma) refers to the fact that the EB development team moved the vanilla city of Rome to Gotland to prevent hardcoded vanilla scripted game events from happening. Yes, Gotland in Scandinavia is actually the code for the vanilla city of Rome relocated out of the way. It's there so the AI never succeeds in taking it and screwing up the EB script.
Unfortunately it's also the reason the AI in RTW generally likes to head north instead of south - most AI factions in RTW are hardcoded to try and find vanilla Rome and take it (to beat the human player), and they search for it like bloodhounds on the scent, e.g. Hayasdan wandering into the steppes instead of going for Babylon like they should.
("Hey, you stinking dirty nomad scum, can you tell me where Rome is before I kill you? I know it's round here somewhere...")
Interesting comment above. I will fully admit that I know nothing about the game coding and my comment could be wrong.
But I have seen this discussed before and thought it was as I mentioned.
Furthermore, just last week in my new Romani campaign I noticed the March of Time event appear the turn that I built Capua into a Huge City.
Roma had been built into a Huge City several dozen turns before.
So I dispute this. But I'm not really sure.
Perhaps someone else could shed some more light on the subject.
Cheers
Yeah, just tested it with cheats. March of Time doesn't seem to trigger when Roma is upgraded to a Huge City. But it does so with Capua.