I'm probably going to get some hate for this, but...
There is a lot of opinions here about what lubricants, and rightfully so. The lubricants run and protect your investment, you want to make sure you're adding the the right fluids. But you also realize that changing these lubricants can seriously damage your wallet. Some would say its the cost of doing business, while others will say oil is oil and your hard earned dollars are best spent elsewhere. Doing your 500hr service, where you pretty much change out all the fluids, is not cheap! I just did mine, as in, finished it yesterday.
I realized that changing out the hydraulic oil was going to be a bear. It holds just over 11 gallons of fluid. Now, not all that fluid will be removed, so lets say 10 gallons max. I went to North 40, it's kind of like a TSC but way better. The manual for my tractor specs API GL4 ISO VG 46/68. But lets put that aside for now, lets get into the store and down the isle with all these different oils.
I see shelves and rows of different colored jugs and bottles. Each one is either specified for a specific tractor manufacture or rating. Of course there isn't one for New Holland and certainly not for LS. But down on the bottom shelf there is a row of 5gal buckets. One says "Harvest King AW-46" on it. Well, turning the bucket around, it meets and exceeds the API GL4 rating. Check the price... $70!! And I need two of these, plus another 2 gal jug for extra. And this is the 'cheap' stuff.
We better keep looing. I walked around a bit, but didn't see any other brands. They carry Shell, Mobil, etc, but not in Hydraulic fluid. To the interwebs! Standing in the store I pull out my phone and press the Amazon icon. Search for hydraulic fluid...
I scroll through the options looking for brands I'd recognize and trust. I find Shell Rotella Heavy Duty Tractor Fluid, specifies API GL4 and is recommended for New Holland (LS) (and others). After taxes, it's $137 and I need two! Moving on, I find Chevron Rando HD ISO 46 for $124. Same story. I decided to go with the Harvest King. Is it the same as TSC Traverls? Probably. Do I care? no, not really. It meets the specifications, and now with 500hrs on the meter, I have not had a problem. And yes, I have been using this same fluid since the 50hr mark.
Hydraulic fluid is not under the same conditions as engine oil. While hydraulic fluid does lubricate and pressurize, it does not get that hot or have that much friction applied to it. Which is why it will last for so long inside the tractor vs engine oil. Hydraulic fluid will absorb moisture though, so it does need to be changed. Growing up on the farm, with our old machinery, we never changed it! Just always had to add more oil when the level got low, due to the various leaks!
My advice on the different lubricants is buy what you can afford and know why. I don't cheap out on the engine oil. I run Mobil 1 in all my vehicles, tractors, small engines, etc. Gear oil and hydraulic fluid is what I find on the shelf. I also am not a stickler for OEM filters. I could pay to have the manufactures name on the filter, or pay half as much and have Wix printed on it.
The 500hr service I just completed cost me about $400 in fluids and filters (thats quick math, I keep a stock of filters and most oils). If I was to use a name brand fluid, it would have been about $500 for the service.
The important thing here is to do the maintenance regularly. Either trailer the tractor to the dealership and pay to have them do it, or do it yourself, but do it. Don't get wrapped around the axle about what brand is what. Spend what you can, and do the work.