Salat has a fixed length

According to 4:101 that during war the Salat can be shortened. Since 4:102 consists of two units and each group does only a single unit, then this must be a shortened form of the Salat.

[4:101] When you travel, during war, you commit no error by shortening your Contact Prayers (Salat), if you fear that the disbelievers may attack you. Surely, the disbelievers are your ardent enemies.

وَإِذَا ضَرَبْتُمْ فِي الْأَرْضِ فَلَيْسَ عَلَيْكُمْ جُنَاحٌ أَنْ تَقْصُرُوا مِنَ الصَّلَاةِ إِنْ خِفْتُمْ أَنْ يَفْتِنَكُمُ الَّذِينَ كَفَرُوا إِنَّ الْكَافِرِينَ كَانُوا لَكُمْ عَدُوًّا مُبِينًا