Invis heroes are difficult to counter for newer players because it's harder to see their weaknesses. Gem is pretty much always the right choice, but it'll require you to make few mistakes during your early pushes, and you have to make the right choices in your early decision making.
Sven is generally played as either a super hard carry or even as a support, but I focused more as a 3 role, which means I'm not a super important carry. By aggressively trilaning like this, it took a lot of the pressure off of our solo Luna as well as our morphling, who aren't the strongest solo heroes. I'm sure a lot of you might consider flaming over arcane boots, but for an early trilane, the extra mana pays off way harder than the 30% attack speed that I would get out of treads. I think the arcanes in this occasional was completely worth it.
Razor is a generally unplayed carry who is quite strong in the early and mid games because of his tankyness and natural damage from static link! You need to build tanky items like Mek, or Vanguard, or Pipe on him so that he can stay alive long enough for your team to back you up, or static link to allow you to deal out some good damage! Make sure you don't get too far into the late game with Razor though, because he peaks off as a hard carry compared to a lot of other heroes.