Here’s why you want a high output in your position.
The Vincent has 2 choices- MM or MC.
In MM mode, it doesn’t have enough gain for the 1 mV output of the low output Grados. But the loading is perfect at 47k ohms.
In MC mode it actually has more gain than you need at 60 dB. 48-52 dB would be the sweet spot for most systems. But the loading is all wrong at only 100 ohms. Run the Grado at 100 ohms and the sound will be very muffled with no highs at all. None. 100 ohms works well with many (but not all) Moving Coil cartridges, but is a definite mismatch with a Moving Iron.
You need a phono stage that allows sufficient gain while also allowing 47k ohm loading. Many phono stages will not accommodate this requirement. Most of the Sutherlands will, which is how I landed on Sutherland. While I’ve owned and enjoyed a low output Grado, I’ve found it’s more important to me to have a user replaceable stylus, which is why I still use the Gold3. If I ever get a wild hair, the Sutherlands are flexible enough to be used with any Moving Coil as well.