I think that correct way these days with Meteor 1.3 would be to put your components to imports folder as mentioned here [SOLVED] Meteor 1.3 not strictly enforcing import/export?
And than import them as you need. I did not tried if classical cascading way works - but I think it should be better to mention all needed imports in every file so also testing can be done without executing additional files etc.
As opposed to hand them up on global namespace in 1 file. But if expect them on some namespace from before, it can enable you to migrate slowly instead of need to rewrite all dependencies for all the components etc at once.
I have not played with it yet, just observed some discussions.