Eisenhower should be lower - they are including his military service as part of his presidency. Had it not been for the decision to drop the bomb on Japan, Truman would have been lowered.
Frankly, I wouldn't rate Washington as a great President for precisely the same reason.
A year ago I would have agreed with you. Lately I have seen two presentations on the Top Secret Corona Project that Eisenhower funded to put spy satellites over the USSR. The project proved that there was no bomber gap (they had less than 50 long rang bombers) and probably no missile gap. Eisenhower was willing to fade the heat over problems that did not exist to keep the secret. Kennedy who ran on a platform to close the gap almost let the info out by changing his tune within days of being sworn in.
Truman stood up to Communism when it was threatening to over run Greece, and come to power in Western Europe through elections, by proposing both the Marshall Plan and the Policy of Containment. Both of those policies saved Western Europe from the fate of Eastern Europe. The situation was so bad economically in western Europe after WWII, that Communism could have been voted in.
Truman made sure the dike held firm in the West until RR could come along and see that Communism fell of its own weight and stupidity.