There is no advantage to cut'n'cobbled foam in the 2x4 stud bays- it only complicates the assembly, costs more, and puts the sheathing at higher risk.
Instead, air-seal the sheathing to the studs with acoustic caulk (use can foam to seal any stud or sheathing penetrations by plumbing & electrical), and install either cellulose or unfaced R15 rock wool (preferred) or R15 fiberglass (which is fine.)
You can then put either 1" XPS or up to 3" of unfaced Type-II EPS on the interior side of the studwall, with either furring or fiber-insulated 2x3 wall on the interior side of the foam. It's important for the foam layer to be air-tight, and it may be worth using something like housewrap detailed as an air barrier between the foam & exterior studs, since unlike rigid foam, it can't shrink or crack over time.
You can't stuff R15 batts into a 2x5 stud bay very easily- they're way too dense & springy, and compressed to 2.5" they won't perform anywhere near R15- in reality it'll be about R11, per the manufactures' compression charts:
The easiest batt solution for the 2x3s would be to either buy R8 batts (designed for 2x3 studs) or compress unfaced R13 batts into it (they will perform at about R10 at that level of compression.)
With 1" of XPS or 3" of EPS it becomes a 1-perm vapor retarder, but at a reasonable location within the stackup from a wintertime moisture accumulation point of view. But with any brick veneer wall it's important that the cavity between the brick & sheathing be vented to the exterior. A bit of investigation is in order sometimes the cavity is blocked at the top, sometimes it opens into a vented attic, but in all cases at a minimum it needs weep holes in the bottom course of brick (usually a gap or drilled hole in the mortar) as well as some venting near the top, to allow convection to pull outdoor air through the cavity. This keeps the average humidity in the cavity close to the average outdoor air humidity, allowing the sheathing to dry toward the exterior. With out the venting there will be times/seasons where dew or rain-wetted brick create mold conditions inside the cavity, since the brick can store a substantial amount of water.