It's just so confusing, isn't it? You go and see 3 different doctors who offer you three different opinions, and usually none of them what you want. At least I am hearing more and more positive stories of people being offered the choice between grommets or hearing aids, not the old chestnut of "watchful waiting" until the child reaches puberty, and not one specialist enforcing their opinion on you. We have been told grommets or nothing, no offer of hearing aids. She is back at audiology in about 6 weeks (oh finally!) and I will push them very, very hard about it. If kids elsewhere in the UK are getting hearing aids then I want some for my DD. Especially as, like you, though they can see some congestion they also think it is not the main cause of the problem.
But for what my opinion is worth, your situation is a bit different. It's very, very hard to get a proper match between and unaided side and an aided side. Your daughter is very young so would at least be the best possible candidate for attempting to aid one side (apart from people totally deaf in the other ear) but it's still tricky. You get normal-sounding sound in one side and processed sound in the other ear. Some audiologists actually prescribe a hearing aid for each ear where that is possible, and just set the one for the normal side to have no real gain in it. That's just to match up the two ears. Since getting hearing aids from the NHS can be a bit blood out of a stone anyway then they may not do this, in which case I'd ask them very earnestly what they think about this issue of normal sound in the normal hearing ear. If the hearing can be correct to near-normal with grommets it might end up being a better result for your situation.
It's very hard to get any sense out of people as ENTs don't know a lot about hearing aids and audiologists don't know a great deal about medical and surgical treatment of the ear. I think it would be nice if patients and their parents could meet up with them both together to discuss things. Don't think of it as a final decision, it's just what you are doing at the moment. You can always turn back and try the other option. Grommet surgery may rule out any of the other suspected problems or it may confirm it, which is why they are dying to operate on my daughter, the grommet op is cheaper than doing further tests!
I'm new, BTW, just finding my feet with the forum, but long experience with conductive and mixed hearing loss cos my mum and I are both deaf to a certain degree and my daughter has a 50dB hearing loss too. Been there, done that, worn the T-shirt! And campaigning for better recognition and treatment.