In my exp it does not work. The better skimmer will continue to skim while the other will just do almost nothing except maybe become a real large air stone. If you just have extra ones doin nothin go for it but its a real waste if your going to spend money on two good skimmers
If you don't have the space or overstocking/feeding may become an issue you can use two skimmers. We use identical skimmers when we do and both always skim like they're supposed to as long as you keep them clean.
IN another thread I said 2 skimmers are better.. Why for 2 reasons having a Venturi and something different both will skim different waste . Which is good in itself . And having 2 will enable you to clean one skimmer today and you will still have the other skimming while the clean one starts to skim again in a day, not many skimmers will work as soon as you clean them and then skim correct it takes time to break in again .. Note your tank would have to be quite full with corals and fish to really benifit . Just my 2 cents.
I used 2 skimmers at one point I had a remora hang on and a marineland pro in my sump then I upgraded the hang on to the prism pro that thing puts out some serious flow the pump on that thing is a beast so it added a lot of movement to my water as well as clean up a lot of nasty stuff. More filtration is always good if you are heavily stocked. I keep a ton of lps so I was feeding very heavily with a turkey baster the 2 skimmers helped my water quality a great deal. Now that I feed with a syringe instead there is much less crap floating around for no reason. Now I use less food so I am only using 1 skimmer but 2 can definitely be a good thing.