Its more kuma's fault than dragons, dragon couldnt risk a war and sacrifice a bunch of men for one person especially when the revolutionary army was still growing in power, Kuma literally could of poofed in grabbed Ginny and poofed back out, they knew the celestials took her and they knew where mariejose was, aint like they got tight security in the Holyland
Fishertiger broke in and freed a bunch of slaves
Lafayette broke in when they had the warlord meeting after crocodiles defeat
Rocks got to the boss level room (100% certain the flower room is where Luffy will have a final fight with imu)
Sabo and a gaggle of revolutionaries broke in and out with Kuma, while freeing slaves and escaped imu and the gorosei
Not to mention even Bonney a literal child managed to sneak in and out
Kuma could of easily got in and got out
