Yes, but armor doesn't work the way you think it does.
Armor acts like a damage multiplier, not addition or subtraction.
So a unit with -10 armor actually takes 46.1% more damage!
However, negative armor caps out at -20, which is equivalent to 71% more damage.
You also have to take into account of the type of armor. Remember that heroes have an innate resistance to most types of damage except from other heroes. Also, armor only works against physical damage.
Your example lineup is viable and can win depending on which tatic is going to be played and player skill of course. However your lineup is forced to go an all in tactic since it will not outcarry the second lineup.
If they can manage to push one lane of rax around the 20 min mark they have a solid chance of getting another lane and win the game around the midgame. Since they have a solid global ganking strat combined with push it will be hard for the enemies to get a solid early to midgame.
But if they play with mapawareness and defensive they will not get picked of too much and stop the first rax push since they could farm their midgame items on their carries.
So in conclusion: Your lineups are not a good example of extreme cases of lineups and therefore can both win.
There are lineups that are unlikely to win. Those are present in AtoD tourneys (DotA reversed) where people pick the lineup for the enemies (making it extremely bad).
For example an 5 hero lineup with no early game presence like spectre, riki , etc.
Those will most likely not win vs a rounded or a strong early game team.
And to answer your final question: There is no lineup for a guaranteed win if we are talking competitive CM mode. If you are talking about AP there are good synergy lineups but nothing that would not be counterable. Dark Seer + Naga Siren + any more aoe heroes was once considered extremely hard to beat and navi did it with a fast bkb on enigma and an naturally magic immune hero like juggernaut.
Final conclusion:
Picking lineups in CM mode is taking away a lot of the game already. Forcing enemies into tactics that they expect to beat is an extreme advantage.
Best Answer
What the commentators were actually referring to was the was one of the secondary effects of Timbersaw's first skill, Whirling Death. The effect is that if an enemy hero is hit, their primary attribute is reduced by 15%.
Since each point of strength is equal to 19 maximum hit points, Whirling Death effectively deals an extra .15 * 19 * the hero's strength points of damage to Strength heroes.
Source: http://dota2.gamepedia.com/Timbersaw