Women in agencies do not write men first. It is the agency worker sending you the letters. If you want women to send you letters first, than join Elena's models.
Agencies are convent for women. The agency writes and reads all letters for them and screen the men who want to visit them in person. Sometimes agencies make up excuses to guys that girls do not want to meet in person. High quality women get many visitors and they need to screen out the men who come to visit them as they can not met them all.
That is why visit often and see many is the best approach. You will know when you found the right one. When this happens stop seeing other women. This process is not really hard. Get away from the letter writing and make a plan on how to visit often.
Agree, with one caveat.
A unsolicited letter from from a RW with a local agency is likely part of a marketing campaign in which the same letter has been sent to many men. The objective is to encourage men to respond and get something started at $5-10 per letter.
With the BETTER agencies, the RW could be newly listed with the agency, or she is an attractive woman who has expressed strong interest in meeting men. Such is exactly what I observed with one agency after speaking to a couple of terps while there.
With the QUESTIONALE agencies, the RW may not have any interest in meeting anyone other than the best men near her age. In fact, she may not even exist.
If a man is working with a local agency, do not take a long time in correspondence. 3 letters maximum to multiple women, and then get on a plane. A phone call is advisable.
Also, when you arrive, there will be plenty of other RW who would like to meet you for an hour.