I must point out that the only reasonable option for Brits garrison counter in teir 1 is the Vickers HMG. That’s literally it. Even then the HMG needs heavy cover or a garrison if its to try dislodge anything with a decent amount of firepower. And its a slow process.
Technically speaking a HMG42 will do the same and will only loose if it has to go against a Vickers (From teir 1 units that is).
A standard UC may work in a pinch but its gonna take a lot of damage (which you can't repair until RE) and will be slow.
Ost on the other hand have three effective options from tier 1
1.) The flamer on pios - very effective.
2.) Mortars – effective, safe and can provide smoke cover.
3.) Sniper – slightly less effective than the brit sniper but comes out much earlier.
The story is little different when both reach teir 2 however ost still have more options with the addition of:
1.) Panzer Grens with StGs and bundle grenades - effective at close range.
2.) Flamer halftrack - very deadly but a little squishy and loose reinforce ability.
3.) Rifle grenades - range advantage.
Whilst Brits get:
1.) Wasp upgrade - effective but very fragile making it risky.
2.) Mortar pits - effective but position dependant, can provide smoke but requires vet 1.
3.) IS grenades - stock standard grenades.
4.) Base arty - bit of a joke and very RNG dependant as well as costly in muni.
Lets not forget that the Ost also get call in units where as brits get bugger all:
1.) Mortar halftrack
2.) Assault grens
3.) Stormtroopers
It seems somewhat disingenuous to say that Brits are as capable at clearing out garrisons when they clearly have fewer less effective options available in the low tier stage. Its not that they don't have tools, its just not gonna be as easy and/or as timely as the Ost options.
You forgot stunnades from the axis doctrinal and commandos as call ins
And you are absolutely right about that ost has multible more ways to attack garrisons. Thats why its called asymmetrical "balance."
My point about the brit was that they can contest, capture and hold any single garrison position in 1vs1 situation at a start of the game because of Vickers ability to kill anything garrisoned --> Until Ostheer musters enough support infantry and mortars/snipers to counter.
And about that MG42 can do the same as vickers... well maybe if given loooong enough time. Even then i thing Mg42 might die before killing the target...