Jintsuu's cosplayer appears to have deleted their account at some point. The other two are tagged in the post as well as mentioned, but sumire_maru is only mentioned. There is a live 2021 account with that handle, but can't be sure it's the cosplayer.
Edit: They left a reply on the tweet for post #9939. Their original account is still live just renamed.
【コス写真】5/8砲雷撃戦！よーい！25
川内改二：くゆさん（@kydy810 ）
神通改二：すみれさん（@sumire_maru ）
那珂改二：春名涼さん（@suzuharuna ）
#砲雷撃戦 #コスプレ