Building units without HE seems to me to be a big waste of

s.
HE costs 300

s. With a forge and marble (+125%) that works out to about 134 base

s.
LB costs 75

s. With a forge that's 60 base

s. With a forge plus HE that's 34 base

s, so HE saves 26 base

s.
X-box costs 90

s. With a forge that's 72 base

s. With a forge plus HE that's 40 base

s, so HE saves 32 base

s.
So HE repays the

s spent in building it once 4 or 5 units are built. That will only take about 10 turns after HE is finished, which should take about 10 turns after the forge is finished.
If there is a threat that Saladin will attack that quickly then all cities should be building military now instead of forges.
Hopefully Sisiutil has been using OB to check out Saladin's cities to look for a SOD that could be a potential threat.