Simple fix to that, don't use the starting setup that the rule book includes. That's just a "quickstart" setup, to get the players familiar with the game quickly.

Here's what you do:

Determine who goes first (the original rulebook that I read said oldest player goes first, most people roll the dice, highest go first, but we roll the dice, highest CHOOSES which player goes first; this has consequences!!).

The player who goes first places a settlement on the board, with a road attached to it.

The next player (in clockwise rotation) places their settlement and road, and so on until the final player places their first settlement (in a 4 player game, obviously this would be the 4th player, remember, the game CAN go up to 6 players with the appropriate expansions/pieces).

Once everyone's initial settlement is in the board, the order reverses. The person who placed their 1st settlement last, now places their second settlement (or if playing C&K, their city) on the board, then the 3rd player, and so on back to the player who went first.

After everyone has placed, deal out to each player one resource of each type that their 2nd settlement (city if C&K) was placed on. If it was placed on two hexes of the same type, they get 2 of that card.

You can see that this order of placement balances the advantage the 1st player has by giving the last player the advantage of choosing both their starting spots at once.