Broadly speaking it is correct. But not so simply. We do all our best to give quality mixed coins to our clients. For example small volume users usually receive a part from a big source, high volume clients receive transfers from several small "quality" sources (was used several times before) etc. With a big reserve we can find suitable sources almost for all transactions.
Clear 
By the way why your customers have to pay 0.0005BTC for each forward address? I used your service and all fees was mush less then 0.0005 (2 times less?).P.S. Don't be offended it is curiosity about service I interested in.