Simplified train shuffling?

I'm wondering whether it's worth adding a simpler mechanism to transfer money between companies. The classic mechanism is for one company to buy a train from the other, at an arbitrary rate. This can be used to get a train where it's wanted or to get a large amount of money into the second company so that it can buy a new train. Managing this shuffling of trains can get complicated.

A simpler mechanism would simply be to let any company aid another when purchasing a new train. There would be no need to work out which existing train to shuffle between the two; one could simply add its money to the other's.

The downsides of this? Well, one is that neither company would suffer any disadvantage. In the existing mechanism, the transfer of the train means that the second company must lose some income (and possibly share price too) before it gets to buy the new train. So you have to trade off the benefit against the cost. With the simpler approach, there would be no loss of income. So the question is whether this level of decision making adds to the game or distracts attention from the larger issues of managing share portfolios and train runs.

In fact, that is perhaps the second downside. If this becomes too easy, will it remove an element of fun from the game? I'm not convinced; given muy target audience, I think this may be worth a try. I can always revert to the tried and tested system if the newfangled approach doesn't work.