Physical is always best in my opinion. Specially for their first games because like others said they can borrow from each other. Later on they can earn or get a present of downloadable games. Will be easier for your little ones not to lose. I only buy physical because you can sell later down the road i collect so collection value is much better and you dont really feel like you bought anything when you get digital. Plus if you think about it you are also gaining more memory with each purchase opposed to eating up your already small amount of memory. Plus you really dont want to have to buy 3 sd cards it can get expensive!
I have to say Namco Museum if you want to play the only game with Download Play. The only game available for it is Pacman Vs. It's pretty fun if you have multiple switches and do not have to buy the game more than once to play multiplayer.
3 kids? Well digitally they can't lose them, but physically they can share a cartridge but if they all wanna play the same game you need multiple copies unless you can play Splitscreen. I would say if you are going to get multiple copies of games buy at least one of them physical to at least sell off one day, but digital is my preference. Also make sure to get some SD cards 126gb ones are around $25ea.
Minecraft is only for download. You will have to buy 3 games of each. Zelda you can get one and let them all share if it's physical but honestly they'll likely fight over who gets to use it. I would just buy all three of them the game. Be sure to get the tempered glass screen protectors tho.!!!
I got it for my sons bday, we got a download version game but he managed to lose the code in all of the excitement. Called the nintendo switch team and they advised that the physical games were better as some downloads weren't working. Btw Splatoon2 and Mariocart are awesome!
