I doubt that the ARX type of brass would be very useful here for such a symphonic tune. Actually I think most of it IS implemented in the SN-A sounds of the Integra. The ARX 03 was structured in a way that a patch was made up of up to 6 individual "players", each consisting of a solo superNatural tone. I don't think you could create a classical trumpet, trombone or French horn section with it that would sound like the SRX 10 ones. IMO it is more useful for pop and bigband (like most Tyros sounds as well).

P.S: Just found the ARX 03 flash demo again. These sounds are for pop and jazz, nothing symphonic about them. The sections are not big enough for that purpose. And they sound exactly like the Integra SN-A brass tones. Not the best Roland has created, IMO SRX 10 is much better (however for a different purpose and without those solo features like falls and glissandi).
http://www.rolandus.com/flash/demos/arx03/