• yatra yatra — wherever
  Doubled relative — 'in each place where.' The same construction Gītā 18.78 will use (yatra yogeśvaraḥ kṛṣṇo). The Bhāgavatam's syntax of pursuit and of devotion share a grammar.
• upalakṣyeta — would appear
  Optative passive of upa + √lakṣ. Lakṣya is the target; upalakṣya is to-be-noticed. The asura strives to be unseen, the devotee strives to see — same root, opposite directions.
• sa-saubhaḥ — with Saubha
  Contiguous join (sa + saubhaḥ) from synonyms. The prefix sa-, 'together-with,' binds Śālva to Saubha grammatically — he never appears without his vehicle. He has become a compound.
• sātvata — of the Yadus
  Sātvatas — the Yadu sub-clan from whom the Pāñcarātra sātvata-saṁhitā derives its name. Naming the Yadus sātvata here links Dvārakā warfare to Pāñcarātra deity-worship: same lineage, different vibhūtis.
• yūtha-pāḥ — the chiefs of the army
  Contiguous join (yūtha + pāḥ) from synonyms. Yūtha is herd or troop; pā is protector. Used for Indra in the Ṛg-veda. Yadu yūtha-pās are pā-yūtha by Kṛṣṇa's authorization — sub-protectors under the great Pā.

• Where could more sustained vigilance change the course of a struggle?
• What helps me stay attentive rather than scattering my response?

Like archers shooting at lightning — wherever the flash appears, an arrow follows — the Yadu chiefs adapt to Saubha's flicker. Devotees in battle hold no fixed target except the Lord's wish; that flexibility is itself a form of śaraṇāgati.