You're probably trading too much and using the dagger to take a lot of face damage. Need to Mulligan for the blackjacks and early drops for tempo. You know all the power cards they have so just try and play around their power cards on curve. I played highlander secret rogue a lot last month as was the most fun deck for me to play. Try and watch a few of your games back and look where it went wrong if you're not sure where it did then in the next game if same situation arises do something different and see if that changes anything, best way to learn
Face Hunter and DH may both be aggro decks, but they work very differently in the way they deal damage to you. It's not super surprising that you can do well against one and not so good against the other.
As for Dragon and Highlander, they're similar decks, both midrange that can turn up the aggression at a moment notice, with Highlander being a bit slower. I played both a lot and Rogue seemed a pretty fair matchup to me tho, barring ridiculous RNG on the Rogue part... as the user above me said, Blackjack (especially in combination with Ambush) is one of your key cards against Hunter, both Dragon and Highlander don't go wide and play a (strong) minon at a time, so Ambush+Blackjack is often devastating.
I think the difference is that hunter can make more damage with less board, it have minions that can't be targeted by spells or are harder to remove (dragon hunter) or minions that do damage in spite of the fact that you can clear it (face hunter) and the hero power can damage you if you gain the board or if you have taunt. Against agro DH that is more based on tempo you can counter that with your tempo plays.
However, i am playing this season a highlander secret rogue and the biggest problems for me are zoo locks, shaman and maybe murloc paladin (the sample is small, I have only played 50 games with this deck)
Just lol. you cant predict the outcome of the cards you'll get offered when you mulligan. you may end up getting even worse stuff than before.
so whats this idiotic advice all the time?
It's increasing your chances of getting something. When I first started playing I generally kept my hand at mulligan because I didn't see the point in it either. I'd maybe ditch really high cost cards because I'd found I'd get stuck with cards in hand. If I'm playing rogue though, I will ditch almost everything, everytime against hunter to increase my chance of getting a stunner and it's helped in mutliple games.
Judging what to keep and what to ditch at mulligan is really important whether you understand or like it or not. If I'm playing super casual I rarely concentrate at mulligan and keep a lot of what I'm given because I'm not thinking too much and those are the times I have my worst win % easily.
As for the OP, it's been mentioned that DH and face Hunter do damage differently and that's just it. It's why I prefer facing DH, I feel like I can play around the tube 5 priestess etc to a degree, save certain cards or play a certain way. It feels aggressive but fair. With FH however the gnomes in particular are very tough to deal with. You take damage even if nothing is actually attacking your face. I've lost multiple games with lethal on board simply because they've managed to get me to 2 health and had explosive trap which leaves me completely unable to do anything except attack and die. Face Hunter is very tough to beat without a really good draw especially for classes without a lot of healing.
Demon Hunter does damage based on board, they have minion after minion after minion after minion after... Rogue never has too much problem with gaining tempo back, I mean, you got Stab, Lackeys and etc. So while you can clear your opponents board, you make one for yourself.
Face hunter at the moment plays burn spells like KC and Corrosive Breath, and they have a good hero power for keeping rogue under pressure. And they sometimes play those deathrattle minions like Sandtrooper and Gnome. So while you are gaining tempo, you are hurting yourself. Toxic Reinforcements can take half of your health by itself.
sure it does increase your chances on something different, i never questioned that ;)
Of course you dont keep a hand full of 8+ mana cost cards for example. Pretty much everyone ( me too ) rerolls stuff that is obviously not useful to have in the opening hand.
But saying you can "actively" mulligan for a certain card just because it didnt show up on the first hand you get offered, is just plain dogsh1t. All you can do is hope for it to show up on the mulligan, just like you hope for some game turning outcome when using your puzzle box of Yogg.
To hard mulligan for a card means you don't only mulligan for a good curve.
It means doing everything to force the game to give you (a) specific card(s). Even if this means that you take a risk on getting higher costed cards that you can't always play in the early turns. So you throw your whole hand if it doesn't give you exactly this card.
For example you sometimes aim on getting galacrond in a matchup, although you can't play it before turn 7.
After the nerfs, I face less facehunter decks, that IMO are one of the hardest matchups for highlander rogue. Dragon hunter or highlander hunter are winnable (in fact I have a positive winrate against them)