I understand your point and see where it could get confusing for the querent, if the readings turn out to be totally differnt, then yes, it definitly would be!
But I have found that usually they coinside,esp. since we have such good readers on the board!
But Vishwas is right, it has its pro's and cons.
If a querent asks the same questions of other readers, alot of times someone else would come out with more info and add to the first reading. The different types of readings reveal different things. I, as a tarot reader, may not see certain things clearly as you, a seer, would be able to, the same as someone who does astrology or numerology might see. They are different types of readings revealing different info. Many times they complement each other.
On the other hand, everybody has an off day, and may not be able to see clearly, i have those sometimes,( shame on me) another reader might be having a good day and see very clearly! The querant will go with the one that sounds most right to him/her. That is why when i feel that i am not seeing the way i should, i suggest you or another reader, so the querant gets as much info as possible. Things will become much clearer for them.
If i have a querant who is asking more than one question, i do seperate readings. That way they get better answers.. I find that i can usually do 5 or 6 readings at a time for different clients, and they always come out different. I read one day a week, saves my energy, and gives me time to take care of everything else in my life.

If the cards don't make sense for a client, i put them away and try again another day. I will not send out a reading that doesn't make sense.
I hope this made sense!