I always find Myiarchus flycatchers to be a real headache, so i will not be much help here. However, one of the birds clearly shows a completely rufous undertail. This rules out Ash-throated Flycatcher, which does not have this rufous colouration reaching as far as the tips of the undertail. The amount of rufous on the undertail would also rule out Dusky-capped. This would seem to make Brown-crested the most likely option. This bird does seem to have a slightly small bill for Brown-crested, but then the only other possibility is Great-crested, which also has a large bill.