Actually Raph216 that won t be easy for some countries and some other countries will not be able to make magic armor (dorgania) for example could adapt to magic armor but they will not be able to give the entire army magic armor you must remember that they have the largest army of all the neighbouring countries plus they could not attack central because of the non aggression pact between the two countries
As for (amagal) they are very good at magic but they don't have a lot of mineral wealth like (dorgania)or(begus) nor do they have a good economy to hire skilled blacksmiths" In fact i think that amagal could help central in stocking up on enchanted bullets in exchange for minerals and workers to help rebuilding there country
and lastly for (begus) begus dose have mineral wealth and skilled blacksmiths but you must remember there mines are over run with undead and they can't make enchanted armor to cover there army with the current materials that they have plus the church dose not want to deal with the undead because there using the undead as an excuse to keep the people in line which will lead to a war between (central) and (begus) which is what i would rather anyway" and after the war ends and (ryen) wins we can get a choice to size power in (begus) or give it to the rightful ruler (Queen jeanne) we can even send (kurohime) to get the queen out of begus because the church started to turn against her
And if we are going to adapt to guns we can go all the way to have cannons and laser cannons the laser cannons could be powered with magic and to have 50 mages power it up until its fully charged and i think (aki) could help with the building of the normal cannons and the laser cannons the normal cannons can be used on human soldiers just imagine arming every castle and fort in central with cannons there won't be a force that could take on central and the laser cannons are for titans
sorry to put a lot of work on u ryen but i really love your work and i believe this game could be much greater than it is now