As UK or any other allie power, I wouldn’t worry if sealion failes, that is G don’t take London.
If G actually captures London then it’s game over for allies.
Sealion G1 in detail with 1 trans bid in Baltic.
2 inf +2 tanks + 2 ftrs + 1 bmr. vs 2 inf, 1 tank, 1 art, 2 ftrs, 1 bmr.
AA fires first, if any planes are hit then G won’t take London.
If no AA hits, then this is about 45%-49% for G capturing UK.
G would get 3 hits statistically, UK would get also get 3 hits in first wave of attack.
Now we’re left with G: 1 tank, 2 ftrs, 1 bmr. UK: 1 art, 1 tank, 2 ftrs.
Second wave of combat. average dice rolls means G get 2 hits, last dice on one does not hit.
UK hits also with 2, the last dice on misses.
3rd. wave of combat. G left with 1 tank + bmr. UK got 2 ftrs.
As you can see, G need very much luck to pull this off, and if it fails, then this is a clear setback for Germany.
I would not be too worried about the rest of the game as playing UK.
No AA hits is not very plausible, it’s precisely 50% plausible.
With LHTR you cannot attack capital with land units during first rnd.
But dice can let you down anytime anywhere in this game.
If Germany walks away with Bank of England then I’m sure this is over.
Not even dice gods can save allies if Germany succeds with the sealion attempt.