Hello everybody, I´m new here but some of you know me from other forums, I´ve been following the forum for a time, but I´ve not registered until today. In any case I´m glad to be here. As I said I think I can help LordArpad a bit:
You can find info on historical tanks and armored cars for Spain and Portugal (and many other countries) in this page
http://mailer.fsu.edu/~akirk/tanks/ , I think it´s one of the best sites for accurate info on tanks up to WWII (models, number of units used by the nations etc...), the main models in the early 20s are as someone else has pointed the french FT17 and the Schneider CA-1 assault tank.
There was some few indigenous development during the 20s and 30s that´s also covered in that page. If you want my opinion with the industrial basis Iberia seems to have you should go for home built models.
As for artillery, this page is in spanish, but it gives nice info on the main models used by the spanish army during the XXth century,
http://perso.wanadoo.es/padron/artilleria/ .
I think you can translate if fairly well with Altavista, but anyway, the main gun models for your army in the 20s should be:
75mm Schneider field gun 1906 model
75mm Schneider Mountain gun 1908 model
150mm Krupp field gun 1913 model
105/11 Schneider Mountain howitzer 1919 model
155/13 Schneider howitzer 1917 model
The last two models were in service well into the 30s and 40s, and were the main guns in service in the spanish army during the first months of the civil war.
Infantry, during the late XIX century the spanish army was composed of about 70-80 infantry regiments (many of them serving in the colonies), and even some of them were dissolved after the 98 war, most of them still existed (and already exist) in the 20th century. As for numbers, usually each regiment had 2-3 bataillons, and each bataillon had 4 companies of 166 men, giving about 1000 men each bataillon. Usually the regiments were organized in brigades (2, exceptionally 3 per brigade), and Divisions were composed by 2-3 brigades too. The tipical is a division with three brigades, resulting in about 18000 men per division. These divisions were territorially deployed, one per each military region, but in case of war could be joined to form army corps and armies.
A list of the regiments and a small history of them in the following page (also in spanish):
http://www.geocities.com/Pentagon/8745/i…regimientos.htm
There were also about 28-30 cavalry regiments (late XIX century), with about 1000 soldiers per regiment, and usually were deployed at corps level (2-3 regiments in a brigade).
About artillery organization, well I´ve not found much info so I cannot help you with that, but look for info on french organization and I guess you can find something quite similar.
So resuming, I think you can easily have about 90 spanish regiment (improved economy) and about 30 portuguese, that´s 120, about 360000 soldiers (about 30 divisions, 10 corps), only infantry, about 30-40 cavalry regiments, most of them undergoing a process of mechanization or just disappearing, that´s about 35000 soldiers more, and a artillery, that´s something you´ll have to figure out, let´s suppose a regiment of medium-light artillery per division, 3 battaillons, with about 18-20 guns per battaillon (3 batteries), that´s 54-60 guns per division, about 1600-1700 guns between 75 and 105mm. Also we can think of about one heavy-siege artillery brigade per corps, about 500-600 guns of 155mm or bigger. Of course this it´s so suppossing all units are at full strenght...
Well I hope that can help you, about aircrafts, most of them were from french or british origin, usually built under license in Spain. As for numbers, I´m not sure, but historically I don´t think there were more than 200-300 at max.
Of course these numbers are for peacetime, in case of war the regiments usually create new battaillons instead of creating new units, during the civil war some regiments got up to 10-12 battaillons.