Trading in a 10 keeper league

Ye i know 10 keepers might be too much, but we wanted something close to a dynasty. We are keeping players based on the round they got originally drafted (even if they get traded), but this makes it a bit weird to trade especially for players drafted within the first 10 rounds.
Lets say you trade for a player who was drafted in round 5. Now you need a 5th round pick to keep him for next year and another 5th round pick to keep the guy you originally drafted in round 5. Trading for a player from the first round seems almost impossible unless there’s a catastrophic injury to the guy you drafted in the 1st.

Any solutions to the problem other than scraping the format?
Some extra info, league is 12 ppl, 1/2 PPR, 17 player roster + 3 IR spots. 1 QB, 1 RB, 2 WR, 2 RB/WR, 1 TE, K, D/ST

My league uses the same keeper format, if a player was drafted they’re kept at their original round value. All FA pickups are valued at 12th round picks. Any players who are kept (we can only keep 2 though) who have the same round value, the owner can keep both and has the choice of which one they want to make the next round up (2 players in the 4th will be 1 is a 3rd and the other stays a 4th). The only exception to the rule is for 1st rounders where the owner needs to acquire an additional 1st round pick or let one of the two go.

Ye we do the same thing. You can use the pick from a higher round to keep 2 players from the same round. But having to keep just 2 players makes it a lot different than keeping 10. Also we have FA pickups count as 17th round which might be a mistake in itself. Got Sterling Shepard a week ago for example who should be a great value at 17th in a “dynasty-like” format like ours.
I reckon the strategy is to keep players with the most value along with your “dynasty core” which are usually the players drafted within the first 5-6 rounds. For example my Kareem Hunt from the 8th is way more valuable than say Lev Bell from the 1st.
Still the issue with trading remains. It’s not easy to trade for someone unless you have decided you will not be keeping the player from the corresponding round yourself.

We used to do the same thing with FA pickups where they would be a last round pick but we changed it cuz 1 owner complained (cuz he rarely makes pickups) that too many players were getting picked up for last round picks and he convinced others we needed to change it to 12th rounders. But yea I see the point of having that many so it makes it difficult. If you can keep 10, you might as well lock it in as a dynasty and alter it to be that.