U2725QE, Lenovo Thinkpad E14, Mac Mini M2 Pro, setup to share mouse and keyboard

Good Morning,

I have a work-supplied (and locked-down) Lenovo Thinkpad E14 Gen 2 with TB4 and HDMI 1.4 ports. I also have a personal Mac Mini M2 Pro, also with TB4 and HDMI 2.1 connectivity. I regularly use both, alternatively. 

I have limited space and want to use a shared monitor and peripherals. For the last year I have been using an Apple Studio display with a USB-C bi-directional switcher, with varying success. In short, the TB4 connection from the Lenovo to the Studio Display is unreliable, whether connected directly or via the switcher. The Lenovo often loses connection, with any open windows 'retreating' to the laptop and requiring physical replugging etc. I have resorted to using an HDMI to USB-C adaptor from the Lenovo - this means I I have two mice, two keyboards, etc. It's a bit of a mess.  

I have been eyeing the new Dell U2725QE with TB4 hub and wonder if this might solve my issues. In an ideal world I would have all peripherals (keyboard, mouse etc) connected to the Dell.

But I note the Dell has only one TB4 input - which I would ideally use for the laptop. How would I then best connect the Mac mini - via HDMI? And if I so, when switched to that input would the Mac be able to access the peripherals?

As both the Apple Studio Display and Dell U2725QE only have one TB4 input, would I essentially be in the same boat?

As you can see, I'm a little confused and hoping some kind soul can help. 

With thanks.