Well, just because many modern militaries have low numbers it doesn't mean you have to be.
They have tiny armies because they don't use it.
Look at the USA, they have millions of soldiers.
In comparison Germany doesn't even have a tenth of this even though their population is around 30-40% of USA.
then look at WW2 when Nazi Germany had almost as many soldiers as the USA during the peak of war, an even before they had more soldiers than the USA currently employs.
It's a matter of necessity.
Post-WW3 atmosphere won't be a kind world so I suppose every decently sized nation can reason a few million soldiers to themselves.

[quote=@MetalLover]
<Snipped quote by Willy Vereb>

While I do agree with this, the thing is, they will still most likely be bitch slapped by the 2 Asian Superpowers. The Caliphate, the GEC, and the Soviet Empire will probably beat them down.
[/quote]I already said that I am more or less just nitpicking since the only thing that matters is the RP.
And if we are at it, Brits will be also hard-pressed against Neo Hungaria if it would ever come to war.
But oh well, we'll see when it comes to it.