Late ascendant and house that rules the mother

Hi all,

Some astrologers say a late ascendant makes a chart unreadable, is that true or it just means a situation has already been decided and something is ending? 

Also, which house rules the mother in horary 4th or 10th? 

I was having a discussion with other astrologers about this in another group and I’d really like more input. 

thank you,

caroline.