That is not right .
Agni-5 : Range = 5000+km , Payload = 1050kg
Agni-6 : Range = 5000+km , Payload = 3000kg
K-15 : Range = 700+km , Payload = 1000kg
K-4 : Range = 3500+km , Payload = 1000kg
SLBM : Range = 6000+km , Payload = 2000kg
You have to compress Indian ICBM to fit in Arihant.
And Surya types wont get into with 10K range.
That is the crux of matter.