i would think that if they max out @ 2Liter per hour, at certain GPH. You use the required GPH for the dripper to calculate submersible pump GPH. You have to charge the manifold with the proper pressure to get a controlled drip
all's you'd do is run a big manifold line, with small outlet tees (creating the manifold) off of the irrigation line. It's a good idea to put a ball valve or something that could slow down flow to certain plants (that require less water)
irrigation line should be larger than dripper lines, to prevent pressure drop (thus the manifold)
the tee's used would be the size of the pipe you are using on the irrigation line, and then the branch of the tee would have the size needed to run a line to the plant
keep in mind, if you plan on cleaning this stuff you want to make things be able to be disassembled. If using barbed fittings, that means you want longer-than needed lines so that you can just cut them and clean and put back together, then throw it out after a while.
or you can used screw in fittings
keep in mind when using a reducer its good for it to be able to be removed, so that the proper sized "bottle brush" or whatever you call it will fit in easily.
if you don't care about cleaning it (prevents drippers from clogging) and can find a way to use throw-away materials and replace X amount of waterings, go for it
a manifold is basically something that helps distribute pressure evenly.
you could make it out of PVC, or flexible tubing, it's all up to you how to design and budget material
