Testa,

You could Dutch your five selections but that will lead to odds-on for almost ever bet and you would have lost badly. You could Dutch the first five SP horses in any race and you would have 80% [over the long hawl] of the winners [again very odds-on] but a run of outs would soon put you in the red too and they happen often [I tried it and it's hopeless].

However, your stike rate for your first two perhaps is good enough to win on and that comes down to deciding on which two to back out of your five.

Cheers and good going.