Sorry, Toni, but I don't agree.
The main problem is that till HM (for top athletes) with a good training we don't have any problem of fuel, because the Super Oil we have in out tank is enough for finishing the race at the max possible speed.
In this case, the limiting factor is the POWER OF THE ENGINE.
When some athlete is no more able to stay with the leaders in a race, it's because has a too much high level of lactate, and can't continue to use the same speed. It's like a car with the engine allowing to run at 140 miles of speed with a max of 5000 revolutions per minute, not able to go at 5500 revolutions, otherwise can break the engine. In this case, for running faster you need to work on the engine in order to increase the number of revolutions, which means the POWER of the engine (more HP).
Instead, for marathon the problem is the opposite. Since we have a tank of glycogen (the Super Oil) not very big, that can last at the Threshold speed till about one hour (after becomes empty), we need to create and use a mixture of glycogen and fatty acids (super and diesel), because the tank of fatty acids is very big and we don't have any problem in that direction.
So, for marathon our main problem is TO REDUCE THE CONSUMPTION OF GLYCOGEN AT HIGH SPEED, while for 10000m is TO ENHANCE THE POWER OF THE ENGINE.
The transfer between one group and the other is not automatic, and in some case not possible.
Athletes having a very powerful engine use glycogen also running at fast pace, but not so fast like other athletes at top level.
In other words : an athlete running marathon in 2:04 or less, of course can run in ideal conditions a race of 10000m on track under 27:00, many of them did it.
But not all the athletes running 27:00 can run under 2:05:0, also with specific training, because not able to change the "fueling" of their engine.
On the other side, don't think everybody running 2:04:00 can run 26:30, since there is big difference between 26:55 and 26:30. There are biomechanical factors influenced very much the performance, with the same level of the bioenergetic and metabolic system.
At the end of every thing, if an athlete has the same physiological attitude for running both the distances at same technical level, needs in any case very different type of training, and can't do the best result in the two events
at the same time, because training is very much different, focusing at different physiological and psychological effects.
Anyway, under practical point of view, an athlete today prefer to be number 50 in the world in marathon than number 10 in 10000m, because the two markets are very different.
But, if we speak about "technical" equivalence, we need to know that athletes with specific attitude for marathon have parameters of resistance well different from what in US you thin : with 28:00 something such as Wejo, you must run a marathon between 2:07:00 and 2:08:00 in ideal conditions, and athletes around 30:00 can run under 2:13:00 without many problems (and after running 2:13:00, if they go to run on track 10000m, may be they run 29:30....).
Finally, we can say that an athlete PREPARING MARATHON CAN RUN A FAST 10000M (may be about two months before the race),
while an athlete PREPARING 10000M CAN'T RUN A FAST MARATHON, because in his specific training didn't change the way of fuelling and is not able to create the proper fuel using in right percentages glycogen and fatty acids.