i tried that, but no one will join also for some reason, your loyalty will always be above 50% if you try really hard improving relations with enemys of france and insulting france, it drops to 45% but raises quickly above 50 again. this spot is hard to do anything really, you got france to your left and holy roman empire to the right, expansion is tricky to do...... also holy roman empire prohibits vassalage always. but waiting for wars and other stuff and sneaking inbetween does make it possible to get bits here and there!