Forcusing on 2HKO victories? That seems to be the way this deck is leaning so I completely support Rubie over conventional choice Oxen. Why not Jose Star though? I don't see Bianca being used as anything other than a 0 pill wall unless you get a terrible draw of 3 2-stars, and Jose does walling better.
Yay, we think alike mahawirasd! =)
I actually also swapped Taigo for Fanny in a Ulu Watu/Uppers DM deck very similar to this I created some time back:
The rationale behind it is that this specific clan combination means you often use Uppers to wall and overpower your opponent with Ulus because of their power advantage. Fanny is more useful in this respect, whereas Taigo would only be useful in areas Zatman and/or Jose Star already have covered.