Reichart Von Zarquon
This is just a minor adjustment that I've found worked really well (and happened by accident due to a misreading of the rules ... don't read game rules drunk).
Bidding on the position cards occurs as usual, with two brokers that are then removed to the position card once purchased and are no longer available for the round.
Continue with standard broker placement, however use only the remaining broker to determine ties.
By doing so, it further limits the control of the winning bidder. They will most likely have last placement and would have that advantage against others. In addition, they probably have highest score among the usual three tie-breaking brokers. If you only allow one advantage to the bid, it is less likely they will have the highest remaining broker at the end of the round and if they are, they have paid for it elsewhere.
No advantage for free!
In addition, the range of brokers left at the end of the turn, on average, only ranked from 0 to 2. This means the likelyhood of a broker to broker tie (especially with 4 players) is considerably more frequent and the unfortunate sod that was hosed during the bidding round may have a chance to recover a little loss since they where probably also stuck with 1st placement. Tactics may shift slightly once encorporated, however, as it may be more desireable to take first position over a later placement, however it keeps to the game style to have a 1st, 2nd, etc. place approach to each facit of the game. Last placement still has greatest power and well worth bidding high on.
For the King's cross variant, simply reuse the two brokers used to bid for position and the remaining, tie-breaking broker (essentially, the usual 3 brokers).