Since theres a imperial guard tactica up, there should be a space marine tactica as well.

You can talk about all space marine armies but try to stay focused on the armies from the Space Marine codex.
So i shall start...

The main tactic i use is a drop pod assault with marines (equiped with cc weapons and bolt pistols and a few meltaguns), veterans, and lots of dreadnaughts. It proves useful when im up against a shooty army such as tau or guard but if im facing chaos or eldar craftworld, i usualy get counterattacked by some incredibly powerful units which nd up carving through my marines, veterans and dreads. Ive attempted to counter this by deploying dreads froma distance with heavy weapons which soften up the enemy and maybe a few scout squads to keep enemy squads occupied. problem is what to do with the marines and veterans. Any help in that?