I am pretty sure I know the opponent in question, as it was done to me quite recently. I did the full attack, came out clean with above average dice for the Japanese.
And i have a game going in OOB where I had my bid as you describe - inf in Yunan, fig in Moscow. The Japanese player left Yunan alone, did not JDOW. We are only on I1, so hard to judge yet.
To start with just the Russian air in Yunan - average losses for a successful attack if you went with 4 inf, 1 art, 1 fig 1 tac and 2 bombers is 4 inf, 1.5 air.
That is heavy for J1. Kwangsi is not easily reenforced at the beginning of the game. In BM, with the guerrilla rule, the loss of the inf plus the loss of 1-2 air is a huge early hit on japan. Russia can be made whole in its defense with UK help, as long as the Allies act accordingly in a coherent strategy. UK1 DOW on japan
would not, in most circumstances, be advised in this case, as it does permit japan to hit the money islands without worry of US intervention. But its a threat that Japan can not ignore, and will dictate some of its movement.
Now, with the extra fig, the odds of Japan winning drop to 66%, with heavy air casualties guaranteed. Not a good bet on J1.
I have been pondering this since it was done to me and i decided to try it myself.
I think the best general strategy for the Axis against a bid that telegraphs this move would be to set up a G2 DOW on Russia on G1, not attack Yunan J1 but position your units to hit China hard on J2, all along the front, but particularly threatening Yunan. And NOT JDOW1. Most if not all the airpower directed to this area. Give the allies a choice of abandoning Yunan to get the Russian air back to the eastern front, or committing to China, and giving the Germans an easier time to get to Moscow.
Still pondering how italy helps, because you need to consider UK1 Taranto, gibastion, or india fleet. But I would think it has to be aggressive to either Egypt or Gibraltar to keep the British pressured; I would think pressuring Egypt would be best, to keep a persian factory from building fighters to send to moscow without worry, but I am not sure.
In the OOB game i am trying this allied tactic, the italians attacked the french fleet with 55% odds, southern france, greece, and the gibastion fleet with 51% odds. Battle score not yet determined. Effects of the overall strat will be hard to determine from this example, as it is OOB and the G1 buy was a dark skies purchase.