Enterprise Rediscovers then Loses the Plot

As a true Star Trek fan I was watching series 3 episode 11 of Enterprise last night.

Here is an episode summary.

Opening Scene:
Present day earth scene, quite obviously out of place with the Star Trek universe.

Immediately you realise there are 2 Possibilities
1) Group of Humans transported from earth by aliens in the past and taken to another planet have developed only 21st century technology.
2) Time travel

Oh wait, plot [1] was in episode 9. Surely they won't do that again 2 weeks later.

So let's sum up this brilliant plot.
1) Bad guys go back in time to change the timeline.
2) Good guys go back and stop them keeping everything hunky dory.

I love the originality. Only one problem - Enterprise (23rd Century?) doesn't know how to travel through time (this is long before Kirk's time). Writer scratches his head and comes up with a true stroke of genius.

How about someone from the 30th century comes back and transports Archer back to the 21st century.

So for comparative purposes, lets put a modern day perspective on this. If someone was interfering with earth's history in the 10th century, possibly leading to all of humanity's destruction I would not trust this job to a fully equipped special forces team to save my butt. No, I'd send in William figgy 13th century Tell with his trusty bow.

Makes perfect sense to me.