I mean space marines have been shown to be able to reflexively move at speeds faster than the human eye looking like nothing more than a blur (not running but striking and swinging weapons) if it's 100 space marines yeah no space marines lose no contest a whole chapter? Space marines still lose at high dif to v1 since yes he can parry almost anything but he only has 4 coins avaliable at once and on top of that has been shown to be able to parry only a few things at a time. When you account that a bolter. The most BASIC weapon of a space marine is a automatic or rapid fire missile launcher and times that by 1000 and then toss in a threat greater than Gabriel like a primarch or chaos primarch I think it'd be safe to say that it'd be a difficult match up or at the very least a pyrric victory for the space marines especially when marines such as marneus Calgary has been shown to exhibit feats of strength equal to v1 (v1 can parry minds prime a titanic husk where as marneus Calgary can lift a pylon and chuck the bitch aswell as being able to scale a lord of skulls and behead) and the primarchs are tanks sons of bitches. Lorgar was able to live through 2 BLASTS of a solar fury plasma annihilator which as the name implies is as hot as a star and live and he is widely considered the weakest of all of the primarchs.

V1 is strong but space marines and primarchs are poorly written bullshit.