Why does the Saboteur/Engineering-tree stand alone? Whats the thing with this tree? Is it just bad in realistic combat and does only dominate on the dummy, or is it just that other Snipers/Slinger not running this tree would be too bad to be listed here in comparison to the named tree?
There's a move called scatter bombs you get in the tree that makes you drop explosives when you use your covered escape/hightail it. The bombs are intended to be spread along the whole path you roll, but if a boss is large enough or next to a wall you can hit it with multiple bombs, sometimes 4 or even all 5. When you do that, you end up getting a huge dps boost from all the bombs hitting. The dummies are next to walls, which means you basically have the perfect conditions to do monster damage while dummy parsing. That's why the sab/eng parses are so much higher than every other spec. There are tradeoffs for doing this in a real boss fight that makes it a lot more difficult, and you can only realistically get close to those huge numbers on a few boss fights, but it's the upper limit of what the spec can do (which is what a thread like this is all about).