> This machine ID MUST be placed in the UUID proceeding the timestamp and sequence counter bits.

I read this as a strange word choice, but interpret as follows: "This machine ID MUST proceed from the timestamp and sequence counter." X proceeding from Y implies that X comes after Y.

If we examine the context, it is absolutely unambiguous (emphasis mine):

> This machine ID MUST be placed in the UUID proceeding [sic] the timestamp and sequence counter bits. This position is selected to ensure that the sorting by timestamp and clock sequence is still possible.

The proceeding sentence makes the intent clear, that a naive sort should preserve time ordering. The only way for this to work is for the timestamp and sequence counter bits to precede the optional machine ID.