149 - Was vishNu's disc such a feeble weapon?

Vol. 3, Book of Forest i.e. araNya kANDA
Chapter 32 i.e. sarga 32
Verse 10 i.e. SlOka 10.
vishNu cakra nipAtaiH
ca Satasho deva samyuge
anyaiH shastraiH prahAraiH
ca mahAyuddheshu tADitam

CONTEXT
sitA, rAma and lakshmaNa were on their exile to forests.
rAvaNa's sister was 'SUrpaNakha'.
She approached rAma and lakshmaNa and urged them to marry her.
rAma and lakshmaNa spoke jokingly to SUrpanakha.
But she misunderstood their words and wanted to devor sItA.
On rAma's instructions, lakshmaNa chopped off sUrpanakha's nose and ears.
Defaced sUrpanakha approached her brothers khara and dUshaNa for support.
khara and dUshaNa attacked rAma.
rAma brothers killed khara and dUshaNa.


A spy Akampana informed rAvaNa about the annihilation of khara and dUshaNa and the defacement done to sUrpanakha.
SUrpaNakha went to lanka and lamented before her brother rAvaNa, about the defacement done to her.
This entire chapter of the 25 verses was devoted for describing the demon rAvaNa.

GIST of this particular verse
rAvaNa's body bore hundreds of welts caused by (Lord vishNu's) vishNu's disc and other weapons, in numerous great wars.

ybrems
*Did rAvaNa and Lord vishNu fight earlier? These battles or wars were not described anywhere.

*Was vishNu's cakra (disc) such a weak weapon, that it can just make some welts?

*vishNu's weapon was supposed to be and said to be the strongest of all weapons, on par with the trident of Lord Shiva and the Shakti of the Mother Goddess.

*Were vishNu-disc's welts like the knife-scars sported by villains in films, as the tokens of their fights and squirmishes?