if you can mount fenders by all means do so for THE most water protection,OTOH fenders get in the way when the wheels are off, they cost more, they weigh more, its harder to mount to a suspension fork, I got one of those DT deflectors on my prophet also my touring bike which has been shipped across the pond a few times and try mounting a fender that will last on a lefty
I think the plastic layers insulate just as well as wool, they wear much better also I find the thicker/coarser wool layers bother my delicate skin, I got polypro 100s tights that must be 20 yrs old but there is no way wool would last that long so I just wear merino if the stink will be a concern like in a BC hut or extended kayak trip but if I can regularly get near the washing machine like front country/local ski touring or biking around the valley plastic is cheaper/more bomber lasts much longer and I think drys faster
Yeah I shop the sales I wait till I can get merino baselayer for 1/2 price and I usually wear them around town as opposed to beating them up in the outdoors… my merino doesn't get to go on a trip till they are full of holes and too beat up to wear around town