Although I am less qualified to chime in here than a lot of the other people, I'll give it a go.
There is no standard bridge shape that can be applied across basses. The feet of the bridge have to be matched to the arching of the top, the height is dependant on the overstand height, neck angle, string length etc. and what works perfectly well for my bass might be a complete disaster on yours. The top of the bridge specifically has a lot to do with the curvature of the fingerboard, which is slightly different on every bass. While you likely have a fingerboard with a curvature that allows for a serviceable bridge shape, that shape could be slightly different than someone else's.
One of the most important factors in getting the right shape is getting the right string heights. This is all about personal preference as well, but generally speaking the top string is around 4-6mm off the end of the fingerboard, and the bottom string is higher, around 8-12mm depending on your playing style, what kind of strings you are using, if you have adjusters, etc. the middle strings are in the middle somewhere to make that a relatively smooth transition. While it may seem like the curve itself is the important part, it is really the four contact points where your strings sit that matter, as they provide the "curve" as far as bow clearance goes.
All of that to say that your bridge being "too straight" between your D-E strings has a lot more to do with the string heights of those three strings, than the curve of the bridge. Measure the string heights of each string, and if you end up with something like G 5mm, D 7mm, A 7mm, E 12mm, then you've likely got a problem.
My two cents? Bring it to a shop and have them look at it. They might be able to modify your existing bridge, or they might need to cut a new one. A properly fit bridge is one of the biggest factors not only to playability, but also to the sound of your bass. You might save a couple hundred dollars doing it yourself, but it isn't worth it if your bass feels and sounds a couple thousand dollars worse than it could.