I created a new collection with the KJV and ESV. The collection keeps defaulting to ESV first so that in the Comparison Tool it uses the ESV as the base. Is there a way to reorganize them?
No. When you specify a collection in the Comparison Tool, it will use the books in alphabetical order.
However, you can just add the two Bibles directly into the comparison tool and bypass the collection: KJV, ESV.
Will they be available on the IOS app in Text Comparison without a collection?
Good question. The answer is 'no', I'm afraid.
In the iOS app, Text Comparison seems to use Prioritisation order for "Top Bibles", and alphabetical order for collections.