As a general thing to be aware of, 2022 cut Timothy hay is likely to be much higher in sugar than usual, essentially because of the UK summer drought affecting growing rates. This affected Timothy grass much more than other species of grass. I buy Timothy from a horse company who are very On It with regards to nutrient analysis, and they've pulled their 2022 Timothy chop harvest from sale as a result. With this in mind, especially if you have older pigs or those with pre-existing health issues, I actually would err towards only using Timothy as a topper on other hay - either to eke out 2021 cut, or to reduce the overall sugar in the diet with 2022 cut.
As I have an elderly and fairly wobbly pig, I'm currently stretching out my 2021 cut of Timothy. When that runs out I'll be switching to Timothy hay pellets, as these are usually made from a later cut of hay, and it's expected that these will have a more usual nutrient profile.