Chiller, what you really have there is two methods, i.e. 4 units on the highest priced of the top two rated and 6 points on the shortest. So over a given period of time, say 100 races you have 100 bets @ 4units, (level stakes) so it either showed a profit (at levels or it didn't) also you have 100 bets @ 6 units (level stakes again) and it either showed a profit at levels or it didn't.

In other words having 4 on one and 6 on the other is irrelavant, you could have 2 1/4 on one and 17 3/4 on the other and the result stands : i.e. you either have a profit at level stakes or you don't. I'd be VERY surprised if there was a profit on either selection though.