The long flap will keep getting in the way. You don't have to keep the top of the Lowepro zippered when shooting. I leave it unzippered.
Also, you are one lens short from filling the bag, so I doubt it is too big. I wish it was smaller but I can't imagine a smaller bag, unless you removed the padding, that could hold 5 lenses, vertically, with one of those a 70-200 and mounted on a gripped body. You can't pour 2 liters of water into a one liter bottle
The Lowepro is also rigid enough so when worn it's quite easy to remove or put back a lens. A softer(er) bag will be a PITA.