I have a spreadsheet where I try to track all of this. Davion and Steiner get a bit complex due to the Federated Commonwealth years in the middle
For house units only (not affiliated mercenaries) active on 3025, 3050, 3067 and 3145:
Kurita: 22
1st Amphigean Light Assault Group
2nd An Ting Legion
2nd, 4th and 6th Arkab Legion
2nd, 6th and 17th Benjamin Regulars
2nd and 3rd Dieron Regulars
5th, 6th and 19th Galedon Regulars
2nd Legion of Vega
6th and 7th Pesht Regulars
5th Sun Zhang Academy Cadre
1st, 2nd, 5th, 7th and 8th Sword of Light (That seems wrong...)
Liao (Yikes!): 7
Holdfast Guard and Red Lancers of the Capellan Hussars
Warrior Houses Dai Da Chi, Hiritsu, Ijori, Imarra and Kamata
Marik: 9
1st, 2nd and 3rd Free Worlds Guards
Ducal Guard of the Fusiliers of Oriente
1st, 2nd and 3rd Oriente Hussars
1st Orloff Grenadiers
Steel Guard of the Protectorate
Steiner: 14
15th, 17th and 23rd Arcturan Guards
2nd, 4th, 8th, 11th and 17th Donegal Guards
3rd Lyran Guards
3rd and 8th Lyran Regulars
1st, 2nd and 3rd Royal Guards
Davion: 25
17th and 20th Avalon Hussars
Sirdar and Valexa Capellan March Militia
1st and 2nd Ceti Hussars
1st, 3rd, 5th and 6th Crucis Lancers
Kestrel, Marlette and Remagen Crucis March Militia
1st, Assault and Light Davion Guards
Dahar and Milligan Draconis March Militia
1st Federated Suns Armoured Cavalry
1st Kestrel Grenadiers
1st and 2nd New Ivaarsen Chasseurs
2nd Robinson Rangers
5th and 6th Syrtis Fusiliers