It would seem like that, but no -- when the ball comes down so fast, two things happen that don't feed it straight to the flippers. It can hit the top of the sling, or the sling itself so it is shot away. Either of which make things much harder to control.
I have set up a number of my games really, really nasty because I use them in the MGC tournament and then leave them that way because I like to play them that way. I do not like to "bastardize" games so much that it totally changes the way that they play, such as putting lightning flippers onto a game that never had them, or changing playfield geometry to make shots harder. Because of that, I avoid certain machines where shots are too easy or repeatable. I like my machines mean and tough.
Anyway, here are some things that you can look at doing: Find out if the game plays well with white rubber. If so, it's bouncier and anything you can do to increase side-to-side ball motion is better. Take rubbers off the outlanes. Use red flipper rubbers. Jack up the back legs all the way with the front legs down all the way. Set ball saver really low or off. Turn off extra ball. Set the machine to "tournament" settings (don't change other stuff though, generally). Make your slingshots *very* sensitive so that even brushes to them can cause side-drains. Rebuild your flippers so they work the exact same, but do not *ever* increase their power by getting new coils or whatever. Then...
Play the game and see what is going on. If you can do something too often, start messing with it to see what you can change to fix it. I was a little worried before this year's MGC because I picked up a WCS that we used, and I was setting it to be nasty, and I was able to get to the Wizard mode and score 2+ billion on a game during the tests. Turns out I just had a rockin' game, as no one that weekend touched that score even with some of the best playing on it. Average ball time was just over 1 minute, but people thought it was really fair.
The good thing about setting up machines really nasty is that it evens the playing field between good and not-so-good players. If a good player can only keep the ball in play 20 seconds more than a not-so-good player, it means the scores won't be too different... BUT, the bad thing is that for new players having machines set up that hard is a turn off, and if you like long, deep games (LOTR / TSPP, I'm lookin' at you) they aren't really satisfying if you don't last more than a minute or two.
I like my games shallow and fair, and personally like my games to last about 3-4 minutes tops. I have a couple machines set up nice for guests though.