Gaster Kingdom has lost a lot of Soldiers as well at the battle of Pameres Kingdom! At that moment, they only had 80 Guards as the remaining 20 were at a task of bringing 10,000 Kilograms of wheat Grain back to their home domain.
At that brutal Battlefield, 50 Guards from Gaster Kingdom's platoon meet with eternal slumber, never to return. It was quite hard going there with 80 Guards and returning with 30! Sure they still have 50 Guards remaining here in the Kingdom, but the wound of such loss still remains fresh. A lot of these Guards befriended each other, had a bond.
Gaster Kingdom can fare quite well with just 50 Guards, it isn't neccesarily a big problem with a Grand Master of Fire Controlling inhabiting the place. Furthermore, Gaster Kingdom wasn't a target by any Domain ever since its mines depleted and the word that the port of Gaster Kingdom continues to earn gold likely didn't get through any ruler's ears.
