Még helyesebben pedig: Nem mellőlük, hanem előlük
It strikes me that this the kind of miscommunication that can only happen in Hungarian. In English you have to screw up an entire three words, but in Hungarian you just have to not enunciate a single "m" well enough.
It is actually not that easy to mis-hear. The single vs double "L" is also a huge difference in Hungarian. The rhythm of the two words is very different.
would this work without first o's?
Would even work a little better that way, I'd say.
Is this one of those situations where "ők" loses its "k"?
Yes. The -k here is already in the -ük. Ők always loses its 'k' when put at the beginning of a pronoun: őnáluk, őalattuk, őbelőlük, őnekik, and so on.
You need just one 'k' per phrase, so to say.
And the ending of these words mark them as "they/them," so I guess nobody misses that first 'k'. :)