Do not just combine them with a 4:1 or 2:1 splitters backwards. I mean if you already HAVE the splitters and connectors and cables to try, sure, try and see how it works for you. But it is likely at best far from optimum.
If you already have mechanical switches or relays you can try those if you like but most will have poor matching and capacitive loading and maybe high inductance too.
Check out the RF direction finding thread on here, they switch between several antennas and it ranges from UHF to VHF and it works "ok". There are probably different suggested designs, but most I think are using diode type switches.
If you want to get some proper PIN diodes they will switch better if used properly. Maybe BAP50? The "off" isolation can be a little weak, maybe 30 orrrrrrr 40dB I guess, check the data sheets and application notes. For more than that you probably need miltiple stages.
Anyway the really "proper" and "easy" way is to use RF switch ICs or mechanical switches that are intended for RF use up to the highest frequency you want to use. But maybe that is too much of a project / expense for you. There are probably amateur radio oriented products you can just buy for a 4:1 or whatever antenna switch with a dial knob but I don't have one to suggest.
If you want to experiment with a diode switch and not buy parts or use even more common ones you might be abllle to make something adequate with 1N914 or 1N4148 common low capacitance switching diodes. I think the reverse capacitance is still around 2-6pF range so not the greatest but probably good enough? Maybe the rf direction finding thread has such examples?
I have an SDR under my bed that I like to listen to at night, I have three cables coming into the bed room from various locations in the house where the antenna are mounted. I'm kind of bed ridden most night so I want to make a box that can just switch between the long wire SW, the little ADSB dipole under the bed, and the 1m yagi. Best would be have the box mounted to a wall next to the bed. But what kind of switch can handle kHz to 2 Mhz with low noise or dropping db? I know it should be in a metal box. Would a splitter work where you lose 3db on each tap work? or would that create a huge antenna that would just kill the band width of the three antennas? Can you use just a regular three way rotor switch?