You wouldn’t want a crewman on the skids above a fire of any significance. Must be a military thing (read ‘We’ve always done it that way....)
Irish military 139’s use the same method for fires, though last year according to fire crews on the ground they never hit the target once on any fire they were called to. Though they can’t seem to ground or hover taxi at an international airport and ATC clearing them without doors open and crewmen hanging out. I’m sure the learned Germans might take some outside input if an avenue of communication was opened?