In addition, the use of a smaller number of arrays allows the system to be much lighter, allowing placement of the arrays at the top of a prominent mast rather than on the side of the superstructure as in the US ships.
The Ticos always suffered from topweight problems so I wondered how the T45s got away with such a tall mast.
A minimum engagement of 1.7 miles might sound good until you consider that a 4 ton object travelling at mach 2.5 - 3 would probably take the ship out anyway, even without a warhead, assuming that the Aster hits. You want to be taking those beasties out as far away as possible...