Those EM272 based mics will give very little stereo separation if used as shown in the photo. FEL should know better than to suggest their use in this way, though I see that they do say as much in the small print below! Omni mics such as these need either a solid baffle between them, or spacing of at least 40cm or so.
If you want to try the EM272 mics, I would suggest that you either buy bare capsules and wire them yourself, or find some pre-wired into a 3,5mm jack. These you can use with your Roland R05 plug-in-power mic input, and save all the hassle and expense of phantom-power and XLRs etc.
The golden rule: Where you place the mics is more important than the mics themselves! Tiny capsules can be placed anywhere and, for cityscapes it's often advantageous to not draw attention to the fact that you're recording.
I have several sets of EM172/272 which I use with my Olympus LS10 with excellent results. One pair is built into the casing of some cheap headphones to give a discreet binaural recording rig. Another option is to clip a mic to each side of a backpack. Wrap each mic in a piece of fake fur or open weave fabric to roughly match your pack and provide some wind protection.
Incidentally, your AT822 is a good, directional stereo mic based on dual cardioid capsules. You can hold it in one hand, point it at something and it will do the job, providing some rejection of off axis sound. Omni mics are omnidirectional so they will record sound from all directions. This might be an advantage or disadvantage depending on the situation. Baffles or wide spacing affect things, too. Experimentation is fun! Only you with your skill as a sound recordist can decide what's best.
Happy sound hunting!