So, Hota wasn't initially designed for online play?
The project has been around for many years, and the idea of playing Hota online randomly appeared relatively recently. Balance adjustments for the castles were made specifically for this purpose.
Added after 26 minutes
it's one thing to set the construction cost to 3333 gold
To make the cost of this upgrade not look out of place against the general background, they made a similar price for some other low-level buildings or upgrades, which may be needed at levels 111-112.
Specifically regarding starting armies - everywhere level 1 is either 10-20 or 15-25 or 20-30 or 30-40. Only centaurs are an exception - 12-24 (which is strange, because they are clearly better than troops with a range of 10-20 - pikemen, gnolls).