Yes MOTH I think that you are right. It's difficult to swap a settler for a sword, but it can be done in our present situation I think. I don't think we HAVE to go to war in EXACTLY 5 turns, but it should be the target.
I posted a war plan some time ago that I still like. The Map is a bit old but it's still fairly relevent.
Yellow dots. Indian war jump points.
Green dots. Dutch war jump points.
Red arrows. Primary Objective.
Blue arrows. Secondary objective.
Start war with 8 swords vs Delhi, and then take Bombay.
5 or 6 turns later attack Rotterdam and the Hague on the same turn. 5 Horses used vs the Hague, and perhaps a few turns healing and reinforcement for the northern stack.
If the RNG is with us, then continue to take the Dutch capital and spices.
End result will be complete control of our sector of the map.
3 new sources of iron.
2 sources of horses (since we take Groningen in the Peace Deal).
1 source of silks min.
1 source of spices (maybe)
No iron for India or the Dutch.
It may be worth thinking about taking Madras too, but primarily the Indian war is only intended to secure our position, get another lux and set us up for the main event, which is the Dutch campaign.