Srimathe Rangaramanuja Mahadesikaya Namaha
That’s called divinity.
Sri Velukkudi Krishnan Swamy used to
say
Pei Azhwar, BoothathAzhwar, Poigai Azhwar never met before but sang the same about Perumal.
My view:
The moment they meet Perumal came. Other Azhwars too had divinity which made them talk the same language & meaning.
Most Azhwars did not meet. Except few like
Andal & PeriyAzhwar
Madurakavi & NammAzhwar
Poigai Azhwar, Pei Azhwar & BoothathAzhwar
That is why they were Azhwars.
They don’t learn from their interaction common connecting point is Perumal.
Naan periya nee periya enbadhai yar arivar?
ThirupAnAzhwar or Thirumazhisai Azhwar cannot say Veda. In fact latter Azhwar reminded Brahmins the verse during their Yagnyam.
Dasanudasan