Dynavector XV-1S ---is it overkill for my system?

JMC is absolutely on the money. You dont put a $5k cartridge on a $2k turntable. If you put a $5k cartridge on, it will be marginally better.
However if you spent $2k on a cartridge and the other $3k on upgrading the tt you will get the best improvement by miles. eg in this case a Lyra Delos or Benz Glider plus additional speed controller SDS, clamp, Antiskate etc.
My experience with the Moon phono's with various Benz, Clearaudio and Dynavectors is a dry and uninspring sound, IMO something like an EAR phono would blitz these, more life, more engaging and balanced.

The tonearm would be the first thing I would replace on that setup.

Sir, I disagree on this matter. I made an impulse purchase of a DV XV1S DV tonearm, and VPI aries TT. I've been a Rega Planar 3 and DV 10 x 4/5 guy for 15 years. I heard this combo playing through Reference Audio Research phono and preamp. This was the best audio I've ever experienced.
I knew my inboard phono section wasn't up to it at 40 db, so I auditioned the Manley Chinook (I'm not up for a 13 k reference phono after this purchase). Though not at the levelof the AR, this combo is extremely musical and enjoyable. The Chinook is probobly underpriced and does fine with the XV 1s . Im not a frequent poster, but hope you check out this combo.

Jasmine pre phono?

Will-herrera,
I've always believed it is better to upgrade the sound path starting with the source. You will not go wrong with an XX-2, I believe Dynavectors do better with the Classic arm than Lyras (I have a Classic 3, and tried both the Delos and Kleos, and was not happy with either).

Of course, the arm, TT, phono stage, and cables need to be appropriate if you are going to get the most out of a good cartridge. As you upgrade the source, the potential performance bottleneck moves down the chain. And discovering thosebottlenecks is what makes our hobby fun!