Ornette wrote:The suggestion that perhaps the members of Seele were to merge with the MPE's
As I already said, there are few quotes, you can justify with this suggestion only by introducing assumptions, which are not supported by facts.
The main one is Keel's words about that everything is going well. Because there are not enough MPEs, everything could not be well. But everything is well if MPEs are needed only to generate anti AT-field.
The second is the meting with Seele at the beginning of EoE where Seele explain their goal (to kill and then resurrect all lifeforms) and it opposes to the goal of Gendo. Gendo wishes to use a Eva to evolve humanity into a new form. Seele say that humans should not abandon their human nature and cling to Eva as Gendo proposes. They see MPEs just as tools to kill and resurrect all lifeforms [using anti AT-field, they probably think that they restore Adam Kadmon from the souls of all Humanity and depart to heaven then, they may not know that actually they will transfer all the souls to the egg], and nothing suggests in the show that they want to merge with them, they would not depart to heaven in this case. Moreover, in the series they directly state that they do not intend to create a man-made god [they are religious society and operate their religious beliefs all the EoE].
As you see, nothing supports this suggestion in the show, and you need to introduce unfounded assumptions to justify it there. Because you consider CI as the second or third tier, you should prefer facts from the show.