yeah... heard it also....
the reason i heard for not having even numbers is because they will 'fight'....
although i always ask my friends who mentioned this..... why can't the 'odd' one be the referee??
don't say deity for your house.... even those (Buddha) pendant ppl buy from thai etc, also must be odd numbers....
then also heard, cannot buy too many, or your 'body' cannot handle....
but to put more the 1 deity, think first, you must be able to 'handle' them.... usually those house with more then 1 deity, are those dang-ki.... cause they know how to handle when 'situation' arise....