Exegesis:

ē tis basileus … ‘or what king?,’ another rhetoric question.

poreuomenos heterō basilei sumbalein eis polemon ‘going/setting out to wage war on another king.’ poreuomenos does not mean that he is already marching but intends do so. polemos also 21.9.

sumballō (cf. on 2.19) here intransitive ‘to meet,’ ‘to fall in with,’ for the purpose of war (eis polemon), i.e. ‘to wage war on.’

ouchi kathisas prōton bouleusetai ‘will not first sit down and consider,’ cf. on v. 28.

bouleuomai ‘to consider.’

ei dunatos estin ‘whether he is able,’ with infinitive (hupantēsai).

en deka chiliasin ‘with ten thousand (men).’

hupantēsai tō meta eikosi chiliadōn erchomenō ep’ auton ‘to meet him who comes against him with twenty thousand (men),’ implying that ‘the other king’ is really the one who starts the war. For hupantaō cf. on 8.27. In ep’ auton the preposition epi is used in a hostile sense.

Translation:

Adjustments in v. 31, where required, will usually parallel those in v. 28.

Or does not introduce an alternative but a parallel example; hence e.g. ‘but listen again’ (Sranan Tongo), ‘so again’ (Javanese).

To go to encounter … in war, i.e. ‘to go/intend to fight against…,’ ‘to go war against…’ (Trukese), ‘to go meet to fight with…’ (Sranan Tongo). Some renderings are built on ‘enemy/adversary,’ e.g. in Toraja-Sa’dan, using a reciprocal verbal form.

Another king, i.e. distinct but of the same category; hence ‘a fellow king/chief’ (Javanese, one West Nyanja version), ‘one-who-is-chief-like-him’ (Tae’).

To take counsel, with oneself, hence, ‘to consider,’ ‘to think’ (Trukese, Pohnpeian), ‘to ask himself’ (Shona).

He is able with ten thousand to meet, or, ‘he is strong enough to meet with ten thousand (men),’ ‘he who has (or, he although he has) only 10,000 (men) is able to meet’; or changing the subject, ‘his 10,000 soldiers will be-able-to war against’ (Pohnpeian). Ten thousand may have to be rendered analytically, e.g. ‘100 companies,’ or generically, ‘very many soldiers,’ ‘large army,’ which will probably entail the use of ‘twice as many,’ ‘twice as large an army,’ or, ‘two such (large) armies’ in the subsequent clause. To meet here is virtually synonymous with ‘to encounter in war.’

To come against, or, ‘to come to fight,’ ‘to attack.’

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.