Short answer, yes, I would expect Grenadiers to win against Conscripts the majority of the time if the conditions are identical.
But as Tycho mentions, luck plays a non-trivial factor in the game. I've lost a fight between a full health gren squad vs. a combat engineer squad because they killed a man as I charged and it got worse from there.
CoH reminds me a lot of poker. You can make the right decision but still lose, but that doesn't mean you should feel bad about it.
I just lost a game the other day when the board came out 3c 5c 9c and I had QhQc. My opponent went all in and I called, and he had pocket Kings with no club. I hit neither a club nor a Queen and lost.
Perhaps a bit of a tangent, but those who are familiar with Hold 'em will hopefully see what I mean.
nice explanation