Ya, I always check the nominal value. It is not accurate but it gives a ball park figure of total military assets.
The employment index gives you the number of soldiers and officers in the army.
The war rank, finance, total score, rank, and level could also tell a lot. I haven't tried using any of them. I usually flip through regions of the map and open about a dozen countries in new tabs. I keep one or two tabs open and go to the next region. Someone might search through the presidents list and look for countries with low (better) finance rank and high (worse) war rank.
On White Giant I found a country with one garrison blueprint that had 1 AAbat, 1 Defbat, and 1 jeep and no nuclear defense in the garrisons. The garrisons were in 20 forts and the cities. The population was 33 million, it had no state factories and no military units. It did have around 5T in military assets which were all missiles and ammunition. That was an exceptionally rare find

and White Giant is much less dangerous then any other planet.
General Bobo may have been thinking of a country with 100 million population. If you have 1 million active batteries then you will have 6 to 9 million military personnel just operating the batteries. Additional personnel have to operate your military assets like forts and the bases. Some government employees are also required. In order to get 10 million workers you also need special clinics, universities, back to work schools, and hospitals. All of them require staff. If you tried to pack 1 million batteries into the country most of it will automatically go into reserves. 10% of the reserves auto-activate with the war declaration but they go back into the reserves at the end of the month if there are no workers available as soldiers.
I flipped through a few countries on Little Upsilon looking for a good defense. Check "a Priest Empire" run by tattooed priest. He has -28T for assets. The map is packed with annoying forts and bases. It would take a few hours of boring repetitive clicking to start putting a dent in the war index even if my ammunition was available and his garrisons did not have supplies. There are swarms of supply units crawling around. If I had to fight a war with tattooed priest I would target his expensive units and try to inflict economic pain. I would not bother trying to take the country. The military staff is at 4 million and total population 40 million. Total military assets $38T.
If you are only worried about random attacks, 2 million military personnel and $20T in military assets is probably overkill for a population of 20 million. The only worry would be if you had enough cash or salable assets available that the aggressor could recover all of his/her expenses.