Good question. That has to do with the timing of both of those licks.
Lick #4 uses four 8th notes at the end of it which is why we don’t want to use the same finger twice.
Lick #5 however uses two quarter notes at the beginning of it so we actually want to use our same finger twice because this is going to help us not rush through the lick.
You could also play Lick #5 the way you’re describing but it’s important to play that pause between the first two notes.
That’s why using the same finger twice to help slow yourself down can be a good tip.
If you have any other questions let me know.
Mike