vim: display relative linenumbers starting with 1

I'd say, work with the system. Instead of using a 'repeat' you could modify to use the motion as intended:

y3j instead of 4yy

You'll notice that the yank command takes a motion. yy is only there as a shorcut should you not want a motion (by definition it takes the current line).

In a sense, doing 4yy is a little bit akward ('4times' take this whole line; You are relying on the fact that the implict motion is effectively multiplied by the repeat, it isn't natural since the motion was implicit).

On the plus side, you could even combine it: 4d3j (delete 3linesdown 4 times in a row, not a very useful example)