The only reason why Species 8472 got one up on the Borg. Was because the Borg couldn't adapt to something they couldn't assimilate. A major draw back in a society where assimilation is the primary source of information.
Still...a few rudimentry sensors wouldn't've gone astray 
As to Borg in my games:
1 scout cube slightly more powerful then the PC's ship. Many crew assimilated including 1 PC.
A couple of 'echoes' to scare the PC's. ie Cubes along the RNZ scoping up things ala TNG 'NZ'.
A 'Q' ep with a alternate future encounter with 2 Cubes on the way to Wolf 359 (explain how the VOY ep with a cube of Wolf 359 assimilated crews)
Wolf 359 itself, PC's won but at great sacrifice and a alternate timeline was made.
Wolf 359 again in a time traveling ep to restore the timeline by the Prophets (PCs indirectly killed Sisko).
So all in all only 2 direct confrontations ( a 3rd indirectly).
ST: Star Charts Guru
aka: The MapMaker
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