If R1 buys a sub, they waste 6 IPC. If they have average or worse dice in taking WR and Ukraine, you should seriously consider forgoing africa and full-pressing Russia. Maybe attempt to take and hold WR, as in case blue:
But I found that just forgoing africa and attempting a take and hold of ukraine can also work wonders. Use your transport to take 2 units off africa, and land in europe. Build mainly tanks and a few infantry.