A switch isn't a mult.
Mults break down into two categories: active or passive.
A passive mult is probably the simplest module in Eurorack. It doesn't require power and splits your signal into two or more outputs. The issue with passive mults is that each additional split robs voltage from the input. That's not a big deal for clocks and gates. But when you're using CV for pitch, there can be a drop in voltage... which will detune and throw off the scale for your CV.
Active or powered mults, are basically distribution amplifiers. They make a copy of the signal at a 1:1 (hopefully) voltage.
Passive mults are less expensive than actives.
The Joranalogue Switch 4 isn't a mult. It's a switch that allows selecting either an input or an output and routing it to a different destination. Depending on the switch it is possible to route one input to multiple outputs simultaneously... but that's going to depend heavily on the design of the switch.