First post here - Had to sign up for an account when I saw this question. Former HS swimmer, 4 years at a D1, NCAA championship attendee. Also a freestyler. To all the gym gurus please take this with a grain of salt, I’m trying to break this down to swimming specifics. Getting right to it…
Right off the bat I think you are on the right track with your lifts in that you seem to focus on heavy compound movements. If you break down the parts of a race you basically need explosiveness, endurance, and flexibility. You get your endurance from the 4+ hours a day in the pool, and your flexibility comes from stretching. You are stretching twice a day right?
Squats and cleans will give you the strength and explosiveness off the blocks. Ensure you are doing heavy back squats as well as weighted jump squats. They look stupid but they help. Overhead plate lunges will help with the legs, as will Tabata squats. Your legs are super important at the end of the race, you will want to train them for sheer power as well as endurance. Nothing is worse than dragging them home the last 22 yards.
Back is important, Pullups, cleans, and regular deadlift will help a lot help here as well. Don’t be afraid to try inverted rows, barbell rows or GHB reverse situps to incorporate your glutes and lower back. Your back will be developed from the miles you put in, but it still needs love too.
Chest and Shoulders will benefit from dips - if only to balance out your large back. Benchpress will help you get the size you are looking for.
Much of your power will come from your core so make sure to do some abs at least every other day. Choose 6 or 8 situp combinations and crank them out - crunches, elbow touches, V-ups, etc. Rep range is your call, but make it suck.
Our weights days started with a dynamic warmup, compound heavy lifts (squat, clean, DL) then usually a circuit of 5-6 movements: dumbell bench press, dips, GHB situps, GHB plate twists, walking lunges, curl-squat-press, etc. Abs usually followed for 12-15 minutes, then it was into the pool.
I think most importantly make sure you have some buddies to train with, it makes life easier. Some days instead of lifting go out and play ultimate frisbee or football - Swimming is monotonous already, you may as well have some fun. Hope this helps.