[NAME]  If you only expect to need dual 1080p displays, then the Dell WD19S would cover your needs.  And based on the power requirements of the systems you're asking about, you could get the standard WD19S 130W w/ 90W Power Delivery, no need for the 180W w/ 130W Power Delivery version.  If the dock doesn't have quite enough USB ports built into it for your purposes, you could always augment that with a USB 3.0 hub with however many additional ports you want, then connect that hub to the dock, so you'd still have a single cable connection to your attached laptop.However, when using a regular USB-C dock with your XPS 13 9305, dual 1080p is the highest-end display setup you can run (you'd be able to run dual 1440p from the Latitude 5420), so if you think you might ever want to upgrade your displays beyond what you've got, then you might want to consider a Thunderbolt dock instead, such as the Dell WD19TBS.  That dock when paired with either one of the systems you're asking about would be able to run dual displays up to 4K 60 Hz each or triple displays up to 2560x1440 each.If you want to look outside of Dell, CalDigit makes Thunderbolt docks that can support dual displays up to 4K 60 Hz each.  However, one bit of functionality you'd be giving up by going outside of Dell would be the ability to use a Power button on the dock to control the system, e.g. if you want to power on or wake up the system from the dock while the system lid remains closed.  There is no industry standard for an external Power button, so that function only works when the dock and system have firmware support for each other.  That will be the case with the Dell WD19 dock family models and both of the systems you asked about, but wouldn't be available with non-Dell equipment.Hopefully this helps!
I am looking for recommendation on what kind of docking station I should get for my new XPS 13 9305 laptop.  I'd like to connect dual monitors (dell S2421HS) and be able to charge the laptop while docked.  I do not need to use the laptop as a third screen and would rather have it closed.  I do have the following I'd like to attach to a docking station, but unsure if possible:  keyboard, mouse, 2 external harddrive, webcam, printer - all of which look to have USB connections. Also, I'll use the docking station/monitor set-up for my work computer and just unplug the XPS and plug in the work Dell Latitude 5320, in hopes that the webcom/monitors/keyboard/mouse can be used by whichever laptop is plugged in. Any recommendations on a good docking station that I could purchase?  Apprectiate the help!  
Recommendation on docking station for XPS 13 9305 with dual monitors