Basically the problem with a radial is you have a bunch of almost opposing cylinders.
Now in order to make power each cylinder has to a be a certain size, many companies built 3,5, 7 and 9 cylinder radials all using a common cylinder size. use the appropriate number of cylinders for desired power. Due the length/height of the cylinders, the length of the connecting rods and the throw of the crankshaft there was very little, if any difference in overall diameter. at least until you get to 11 cylinders in each row. Because of the number of cylinders acting on one crankpin trying for high rpm was rather difficult.
At any given time in history you were only going to get so much power from a single cylinder ( most aircraft engines, even liquid cooled V-12s started as one or two cylinder test rigs) due to limits on fuel, limits on cooling (number of sq in of cooling fins per cylinder on air cooled engines) and limits on rpm (limits on materials). Basically anybody trying to build a 500hp radial in the late 20s was going to come up with a 9 cylinder engine of between 1340 (or a bit more) and 1750 cubic inches.
Several companies did try to build small diameter 14 cylinder radials, The P&W R-1535, the Bristol Taurus and the Gnome-Rhone 14M.being the most common. Germans used it on the Hs 129.
The last was the champion of small diameter at just under 1 meter but it achieved that small diameter by using a small displacement, 1159 cu in which is a result of using small cylinders 122mm bore and 116mm stroke. Few large aircraft engines were over square but this helped hold down the piston speed of this high rpm (for a radial) engine. 3,030 rpm. Production engines were limited to 700hp and one announced but not flown (?) engine was rated at 820hp.
However a two row 14 is longer and heavier than a single row 9 of the same power and has a lot more parts. Two row 14s became really popular when using cylinders of similar size (usually just a bit smaller) to the big 9 cylinder engines in order to provide much more power than the 9s could. (or to avoid cooling problems and vibration of the rally big 9 cylinder engines).
The smaller diameter of the small 14 never really paid off in streamlining as the more powerful 1520-1820 cu in 9s just bulled their way through the air.
I would note that P & W actually went to longer connecting rods with a piston pin placed higher in the cylinder on post war "C" series engines. Kept the same over all length of the assembly and same diameter engine but lowered stress and added to engine life (less side thrust?).
Now if you want low powered engines then they made a host of 5, 7, and 9 cylinder radials of 55 to 300hp, the smaller ones being rather small in diameter. For some reason this was national. The US having quite a number of different small radials and very few 4 cylinder inlines before WW II, while Europe and a host 4 and 6 cylinder inlines and very few small radials. Post war the US flat four and six engines quickly dominated the market for light planes.