[quote=RogerD]
The other issue is that Space Marines are like America + and it would basically overwhelm everyone else too.http://www.comicvine.com/profile/strider92/blog/space-marines-respect-thread/92848/Sorry dude, but they're too much no matter how awesome they are.
[/quote]

Also, after reading those posts about ships power, I would like to point out that all of those posts refer to entire fleets of vessels, rather than a singular one. Plus, if we're going with the ability to glass a planet, Star Trek ships have that very power. Khitomer was glassed by 3 Romulan Warbirds in the space of an hour. Those posts say that it took hundreds of Imperium ships the same time to do the same job.

And again, I'm gonna call Phasers to the stand, considering that a single Hand Phaser is able to level a building (Actual quote from Commander William T. Riker). Plus, thinking about it, The Galactic Empire has roughly the same technology as the Tau Empire (Minus the railguns), which are known to give the Astartes a run for their money.

When you really think about it. Astartes are physically superior, no doubt, but everyone else is far more technologically advanced. 40K tech is the Warhammer (Pun intended) to Trek tech's nimble Rapier.