Depends. Leadership criteria varies between groups (and I would argue that the elder/presbyterian model is the oldest and clearest in both OT and NT). The decision is of course personal and social/communal, in one's context, but I disagree as to your dual standard rule. The Gospel is also not merely 'spread' but rather 'lived', being a living testimony, a cloud of witnesses per se.
Paul's pre-supposition is anti-fornication, anti-molestation, and a-sexuality. 1 Cor 7:1-2, "Now concerning the things whereof ye wrote unto me:
It is good for a man not to touch a woman. ... to avoid fornication" (dating back to
how marriage and pro-creation originated, from Eve, the serpent, Adam, and sanction from God to pro-create)
Without spelling it out our current generation/era is disgracefully tainted by the very opposite kind of men, perverted, twisted, lustful, twisted, and even the best and purest are tangled in the toxic culture and influences described earlier. Hence the church's stance and priority (in most if not all groups) is defensive and preventative. To shield/protect the congregation, women, and children, out of due diligence, and political correctness. In case. - But this should not be the standard, as a sanctified renewed person should need no correction.
1 Cor. 7:9, "But
if they cannot contain, let them marry: for it is better to marry than to burn." The statement is conditional.
Contain > marry > burn.
"Single men needed all over the world not locally" - Per the above Pauline pre-supposition. Assuming you're referring to single missionary men, there are many cases of overseas pedophiles, child inappropriate contentographers, molesters, and typical adulterers running a muck in the field. Men abroad are no different to men locally. Hypocrisy is not geographically limited. If a man can't control himself at home, he can't control himself abroad.
Such 'self-control' or 'continence' (ἐγκρατεύομαι,
G1467 - egkrateuomai - Strong's Greek Lexicon (KJV)) applies to both, local, abroad, male and female, young and old, unmarried and widowed. It's a pursuit of perfection, becoming servants
of Christ, not wives. Serving an eternal purpose, not the perishing.
1 Cor. 9:25, "And every man that striveth for the mastery is temperate G1467 in all things. Now they do it to obtain a corruptible crown; but we an incorruptible."
The goal is to chase Christ, not brides...