Connecting anchor lines

No windlass but do have a pulpit that has a permanent line keeper (not sure if there is a name for that) so the knot will have to pass thru that.

Never thought of splicing.
 
Why the long splice over the short?

Short has more strength.

The increased size won't cause and issue coming over the pulpit.

Is there something I'm missing with the long splice?
 
Long splice results in a smaller diameter but if that's not an issue you should be good with a short splice.