1. You can transport units from S Eur to Libya and consolidate so you have 6 German ground in Libya at end of G1. This allows Germany to make a serious play for Africa regardless of the fate of the Mediterranean battleship.
2. If Russia wants to spend precious precious air on a shot against my German battleship, they’re welcome to it.
3. If Russia screws around with anything but inf/art/tank, it opens the door for early German control of Karelia, particularly if Germany abandons Africa. (They don’t HAVE to abandon Africa, but if they DO, it’s much harder to stop Germany). One or two units can make a big difference in the balance of power.
Re: German control of Africa: German control of Africa and preservation of the German Mediterranean fleet can be a big plus. Germany has more income. Japan doesn’t need to devote as much power to Africa, leaving it to put more pressure on Russia - and with a KGF in play, Japan’s will be the main attack.
That isn’t to say the Germans HAVE to be in Africa. But if the Germans can get into Africa without giving up too much position in Europe, it’s something to think about.
To answer the OP - if Russia buys any non-ground units on R1, I’m immediately thinking about ways to make major major nasty attacks. Like “Break West Russia with Germany or secure Ukraine, build 8 G1 tanks, build 2 ICs with Japan, and tank tank tank east and west” - that sort of thinking. It might not be possible to smash Russia up real fast, but things can be REAL nasty real quick if Russia leaves 6 infantry on Buryatia, or bled strength off towards Africa/India, or did anything else not along the lines of a UKR/WR open.