Arjuna is nowhere near Ravana. Ravana can only be killed by Rama and no one else .
Celestials praise Rama / Ravana yuddh only being comparable to Rama / Ravana Yuddh which means no one other than Rama is capable of killing or fighting Ravana.
- एवं जपन्तोऽपश्यंस्ते देवाः सर्षिगणास्तदा ।
- रामरावणयोर्युद्धं सुघोरं रोमहर्षणम् ॥
- "While uttering these prayers, the gods accompanied by groups of sages witnessed the terrible and hair-raising battle between Rāma and Rāvaṇa."
- “The battle between Rāma and Rāvaṇa can be compared only to the battle between Rāma and Rāvaṇa itself.”
- रामरावणयोर्युद्धं रामरावणयोरिव ।
Arjuna with all of his powers and astras at best would behead Ravana one time if he is lucky but that would do nothing because Ravana can regenerate infinitely
- एवमेव शतं छिन्नं शिरसां तुल्यवर्चसाम् ।
- न चैव रावणस्यान्तो दृश्यते जीवितक्षये ॥ ५७–५८ ॥
- "In this very manner, a hundred heads of equal splendour were severed, yet no end to Rāvaṇa's life could be seen."
Ravan possess many infallible weapons of Brahma which only Rama is capable of countering them. Arjuna was literally swooned by much weaker warriors like sampastakas. Ravan defeated sugreeva who is someone almost equal to Hanuman in strength with one arrow .
- स सायकार्तो विपरीतचेताः कूजन् पृथिव्यां निपपात वीरः ।
- "Struck by that arrow, the hero Sugrīva, his consciousness disturbed, fell to the ground groaning."
If you read the digvijay yatra of pandavas . They couldn't even defeat minor vanaras like mainda and dvidvida properly. Ravan would crush Arjuna is any encounter