This was very much the case when the Orks were first released. All of the factions found the orks very easy to kill as the orks could only resort to swarm melee tactics to cap a single point. Orks would lose 9 out of 10 games during that time. Also it's a match based game so putting the orks in as a weakling race with huge numbers wouldn't work with just 15 orks on a single skirmish map.
Ya I'm definitely not advocating that Orks should be weaker because of lore or anything. I just don't think their current increased melee survivability is lore logical or balanced by other in game drawbacks.
In which case I would refer to their giant melee hitboxes and qualify that by saying +50 HP is probably too high.
I personally think its the melee system itself that is causing such a bad experience. This includes the Eldar melee being OP too. They've got to revise the melee system that doesn't resort to players spamming the crap out of everything.
Good thing they all wear power armor then right? The Orks got more health because there were a lot of irrational complaints about how weak they were when they really weren't. And that's coming from someone who actually played them a lot. Right now absolutely nothing justify this extra health, it makes them straight up better than other factions.
Uhh, we have three attacks in melee. One is only useful as an interrupt to another type of attack. I'm not sure how we could possibly do melee without spamming something.
They are a horde race lore wise. Weaker then a marine in most aaspects. Their armor is weaker, their melee is weaker, and their shooting is weaker. Generally they rely on their numbers to overwhelm the enemy. Some Orks are stronger though, Nobz, and these are stronger then the average marine I believe. The fact Orks are "the best in melee" and "The toughest" is actually completely unfriendly towards the lore and 100% a balance decision. When this game was going to have the Free2Waagh option, they were gonna be much weaker and more lore friendly but that idea was scrapped (not that I blame them, a cool thought but wouldn't of been fun to play as).
Of all the problems this game has, especially balance wise, you're going to complain about the worst faction? This community is fucked.