Not the same- but what most would consider better. (3) 1's gives you 1.3 times more total drainage capability as compared to the original 1.5 drain. However, you actually get 2 times the linear drainage contact area (the total linear "waterfall" length) - so you should be even better in terms of surface skimming (assuming they are in some sort of stand pipe arrangement).
Funny how that math stuff works...
(Of course the "better" is really an assumption based on those two drainaige systems in the same size tank- in a bigger tank that should have more flow - I made no assumptions about the total flow necessary. Also, that doesnt consider the fact that the flow will be more restricted in the (3) 1's because of more wall contact area).
(I leave those decisions as excersizes to the reader) ...