With the IRHT, OKW has the best sighting tools available, bar none. Without the IRHT it is difficult to say which faction is the best (UKF, OKW, OST or Soviets). However, I know for sure that USF are the plebs of stock scouting options.
While I like Shanka's suggestion, I have a feeling it might not be easy to implement. Thus, Australian Magic's suggestion comes as a strong second.
Now, regarding the stock IRHT, also consider that OKW is also getting stock MGs. Now, can somebody inform me how they plan on flanking those MG34s in the next patch?
For reference, here I am listing all non-doc options for all factions.
USF
M20 (50 - 60 range depending on Vet).
- Dies to 1-2 shots
- Costs 340 MP to replace
- Unsuitable for late-game
Stuart (requires Vet2)
- Good luck replacing that Vet when the Stuart dies
AT gun
- Vet1
- It's very clunky to use as a spotter
Major recon
- Difficult to aim (have to move major)
- A single pass is definitely not enough to give vision for the USF paper forces
UKF
Pyrotechnic supplies Tommies
- Stacks with Vet1 bonus
- Highly recommended
- Easily replaceable
- (just never use the 25pdr ability; it sucks)
Sniper
- Also gets Vet that allows it to spot even further
AEC
- The best unit to escort a Firefly fleet
- Churchill is for plebs D:
Tank Commanders
- Sight range 35 -> 45 (Cromwell, Comet)
Universal Carrier (next patch)
- Vet1 replaced by +10 sight range
OKW
Kubel
- Useful for the first pushes
- 360° always-on maphax at Vet1
- Not easy to replace once dead
Puma
- Best AT light vehicle in the game, bar none
- Easy to replace
Volks grenadiers
- Vet4.
- Pioneer-like sight-range on the most spammable unit in the game.
- What could go wrong?
- Ever wondered why Volksblobs are always able to home in on your tanks? That's why.
JP4
- 45 sight range at Vet0
- Self-spotting at Vet2
- The true wonderchild of CoH2
IRHT
- The topic of this thread.
- Duh.
OST
Scout Car
- Great sight range (insane with doctrinal scopes)
- Durable, easy to replace
Pioneers
- Helps avoid an MG ambush but little beyond that
Sniper
- It's the most frequently encountered unit in OST arsenal
Soviets
Flares
- Sniper
- Mortar
- Tripwire door-flares
T70
- Recon mode
- There aren't many other worthwhile vehicles in the soviet fleet; easy to replace.
SU-85
- Cone-of-sight