It's hard to give advice on different recording setups without practical experience. But I think using an H5 along with the two Samson mics would work OK for in-person interviews. Depending on the environment, the built-in mics might be enough. It just depends on how noisy the environment is and how close the two participants can get to the mics. Still, having the external microphones will give you added control.
You could incorporate the H5 into recording Skype calls but it might be easier to get a USB microphone or headset, connect that to a computer and then use a Skype software recorder. If you've got access to a Mac, eCamm Call Recorder is a good recorder for Skype calls. There's a program for Windows called Voicemeeter that can help with recording Skype calls, as well as other programs.