I agree the Cambridge 'East Trojan' sounds strange.
"oe" is pronounced variably these days. We haven't had an American contributor, but since they spell it "estrogen", that might account for the /e/ pronunication. But they still say /fi:təs/ for 'foetus' or 'fetus'.
But it's /ə'sɒfəgəs/ for '[o]esophagus'.