even if they brought horse and succeed in not getting massacred, they impact might simply disappear in a generation.
It was difficult to maintain technology without underlying infrastructure.
it was extremely difficult to change society.
metalworking would need forge and blacksmith. even if they have blacksmith onboard, its unlikely he knows how to build forge, also its unlikely he can build one without bricks and other necessities.
horse would need male and female to breed, even if they have both, some grass would be poisonous to horse, even if they can keep it alive in menagerie, they might succeed to convince others to breed it en masse.
and that assuming they received and welcomed by local Kings. they could easily forced to join local craftsman/farmer for a living. or even enslaved.
and without immediate benefit, their technology could easily ended up as curiosities instead of absorbed and utilized by succeeding generation.
tech transfer or 'uplift' is very difficult.