[Pibwl]

Does speed of spotter planes matter?... Accidentally, while checking the Czapla, which was somehow faster than basic Polish spotter Lublin R.XIII, I noticed, that most spotters in the game have speed=1, regardless of their real speed, only few are faster, and Hs 126 is an exception with speed 4 - while not being the fastest plane.

(BTW: Polish 618 LWS Czapla was in fact known mostly as RWD-14 Czapla, as Blazejos mentioned - LWS was only a manufacturer of RWD design)

Here is a quick list that I made, with max speed in km/h (the values are taken from Internet pages and they may vary, but they're enough to give a hint). Cruise speeds, which might be more important, were usually lower by 20-40 km/h in speeds below 200, 40-60 km/h in speeds around 300, and 100-200 km/h in speeds above 500 km/h.

Germany
186 - Fieseler Storch - 175 - 1
187 - Fw 189 Uhu - 374 - 2
410 - He 46 - 257 - 1
589 - Arado Ar-196 - 320 - 3
782 - Hs 126 - 356 - 4

USA:
121 L4 Grasshopper - 140 - 1
360 - Curtiss P-6 - 311 - 1
361 - Curtiss A-12 - 284 - 1
362 - Boeing P-26 - 377 - 1
660 - Douglas O-2 - 216 - 3

USMC
090 - Vought OS2U - 292 - 1
095 - Piper NE-I - <200 - 1
135 - Curtiss P-6 - 311 - 1
136 - Boeing P-26 - 377 - 1
283 - Curtiss Seahawk - 504 - 1
319 - F3F-2 Littlecat - 425 - 1
321 - Douglas OD-l - 216 - 3

UK
114 - Auster Mk.IV - 209 - 1
148 - Lysander - 341 - 1
340 - Hawker Hart - 298 - 3

France
046 - Potez 63.11 - 425 - 3
141 - Auster Mk IV - 209 - 1
231 - L3 Grasshopper - <200 - 1
232 - Potez 25 - 208 - 1
236 - Breguet 19 - 230 - 2
565 - Potez 39 - 249 - 2
566 - Breguet 270 - 236 - 2
567 - ANF Mureaux 110 - 320 - 3

Poland
097 - Auster Mk.IV - 209 - 1
601 - PWS-26 - 201 - 1
603 - Lublin R-XIIIA - 177 - 1
604 - Lublin R-XIIID - 185 - 1
605 - Lublin R-XIIIG - 175 - 1
616 - RWD-8 - 175 - 1
617 - PZL L-2 - 183 - 1
618 - LWS Czapla - 247 - 1
619 - LWS-3 Mewa - 360 - 1
626 - Potez XXV A2 - 208 - 1

Japan ...here we have quick ones:
114 - Mitsubishi F1M - 365 - 4
210 - Aichi D1A - 309 - 3
211 - Aichi E13A1 - 375 - 3
212 - Kokusai Ki-76 - 178 - 2
213 - Yokosuka D4Y1-C - 545 - 6
217 - Nakajima Type91 - 300 - 3
642 - Yokosuka E14Y - 246 - 2
644 - Mitsubishi Ki46 - 604 - 6
645 - Mitsubishi 2MR - 204 - 2
647 - Kawanishi E7K - 276 - 3
648 - Nakajima C6N - 610 - 6
649 - Seversky A8V-1 - 316 - 6

If it's useful, I can check the rest. I can also write down cruise speeds.

Provisionally, I'd suggest speed:
- 1 for aircraft <210 km/h (including Auster, Potez 25 etc with cruise speeds well below 200 km/h)
- 2 for 210-300 km/h
- 3 for 300-400 km/h
- 4 for >400 km/h
I don't think, that any spotter flies much faster performing spotting.