With larger distances, less population density and increased attrition & a more mobile russian force... it would pretty quickly go
"Hattin". More or less as historically.
Afterwards, there would be a countersurge and the former order lands would become Russian. A much needed respite in income from the Mongol yoke. Perhaps even resulting in a earlier breaking of the hordes?
And yes, the possibility of that russian-lithuanian merger. Which most definately would quicken the end for the hordes. Infact, the hordes would be looking at extincion within 20 years of such a merger, a possibility that would act as a very strong motivator.
What would such a russian-lithuanian merger look like tho? Tsar with local princes and strong veches? No doubt ultimately resulting in a tripleunion of russia-lithuania-tartar, in order to keep the subdued hordes under some kind of semi-autonomy. Much of the old hordelands settled ofcourse, but the central asian steppes would still be cattle land.
With the orthodox church reigning supreme, as the lithuanians would have had to convert earlier as a requirement for the original union.
Thus the tartars would convert too in order to claim political rights.
And assuming it doesnt all fall apart, which is certainly a possibility, or become a collection of squabbling princes in constant civilwar and thus end up under the polish empire & converted to catholicism (haha!).. there are possibilites for a dominant future.
And thus a 1600s onwards that is quite unrecognizable today.