there are no [Dell display] drivers for Mac
There are no display drivers for Mac for ANY display -- the Mac simply does not work that way.
Drivers are provided for supported Graphics cards.
When your display is connected, it is supposed to identify itself and its capabilities. If it does so correctly, the Mac will automatically set a resolution that is appropriate for the abilities of the display without damaging the display.
As you discovered, DVI displays wider than 1920 wide require a Dual-Link cable, so-called because the data conductors are doubled to support the higher/faster data requirements of wide displays. Dual-Link has nothing to do with Dual Display.