Good News Bible and Contemporary English Version start a new paragraph here, since there is a change in speakers. Other languages may find this helpful.

But they tried to dissuade him, saying: The pronoun they refers to Judas’ soldiers. Good News Bible renders But they tried to dissuade him as “His men tried to talk him out of it,” which is idiomatic English. Another possible model is “Judas’ soldiers tried to persuade him not to fight the enemy.”

We are not able: In Greek this is a very forceful denial. Colloquial English could say “No way!” New English Bible is good with “Impossible!” Translators should find an expression in their language which indicates a forceful denial. A model that places the final clause after this one is “It’s impossible! There aren’t enough of us.”

Let us rather save our own lives now: Good News Bible is good with “Let’s retreat now and save our lives.”

And let us come back with our brethren and fight them: Our brethren are the Jewish men who had deserted; the pronoun them refers to the Syrian army. The remaining Jews intended to get the deserters back, so that they could fight together against the Syrians. So we may translate “then we can return with those who deserted and fight the Syrians.”

We are too few: Good News Bible provides a good model here.

An alternative model for this verse is:

• Judas’ soldiers tried to persuade him not to fight the enemy. They said, “It’s impossible! There aren’t enough of us. Right now let’s just save our own lives. Then we can go get those men who deserted and come back and fight the Syrians.”

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Maccabees. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here.