Two problems with that strategy:
1) Many Democrat voters do not really respect veterans.
2) Republicans have better veterans because they actually stand for freedom.
candidates with a military background on their resumes appeal to independent voters
They're not playing the black or the white keys; the strategy is to stay in the cracks.
The Dems know they have run as far to the left as they can go and now have to try to play themselves up as a centrist party to regain power. They are going to ditch the radical Bernie faction and scramble towards the middle as fast as they can, cloaking themselves in the flag they have long sought to burn.
Part of the reason for associating Trump with the Russians is that the Dems are going to try a “visual” party switch where they convince the mooshy middle that the Democrats are the real inheritors of the Reagan revolution and the Republicans are the abode of old Russian-loving communists.
Recall they pulled something similar years ago in trying to ditch their racist history by falsely associating it with the right, claiming the parties “switched” when all that really happened was that the communists took over the Democratic Party and hid their overt racists under their bed in case they needed them some day.