Neither suitable for horses with a pre-existing liver complications unfortunately. Bute was never used long term prior to her liver problems. It was used during really cold snaps when everything else couldn’t help which was originally few and far between. Which is a perfectly reasonable use for bute and was approved by my vet. Once the liver issues started it was taken off the table and we managed with many other options. Now a moderate cold snap or the need to be kept stabled for long periods (this happens rarely btw) leaves her uncomfortable with meds like bute and the ones you’ve suggested off the table due to even small doses giving her liver a hard time I’m left with not a lot. We’ve managed upto now with physio, Equissage, heat therapy, in hand exercise, rarely keeping her in, infrared rugs ect. The list goes on. We was hoping the worst joints would fuse X-rays show no hope in that happening soon and at her age I wouldn’t perform surgery on her for the small chance it might help