If not for record and history purpose I don't see any reason why Liverpool should waste or stress themselves to... Because they have won the trophy already if I am the Liverpool coach I would have used my second eleven and my upcoming boys to try there strength and also see there capabilities and it is a period like this these category of boys or players are supposed to be test because if you don't play or use them you can not tell there strength and capability. Arsenal has always been a loser for some years now despite there outstanding performance and I think they should stop this history or record before it becomes alarming and usual.
You are actually making a point and I also stand by you, with the look of things they really have to stop stressing the first 11 since they have on won the trophy. When you talk of record I don't expect anything to happen regarding Salah being the highest goal scorer, I will expect a lot of seriousness despite winning the trophy if they are on the track of unbeating but currently they are not so this will coach decision to decide. Liverpool really have an amazing season both in all competitions they played.
On the other hands regarding Arsenal issue, at this moment I came to realize that Arsenal management are not interested in taking trophy, because this is almost five good season now that they are playing a very beautiful football, but they seem to decline at every end of the season even when they have chance to lift the Premier League title. I really pity their fans for being patient for a long time but I hope one day they will make them proud.