Believe or not i agree with you
I'm the first that find awkward as fuck the lion vs tiger internet thing for example, with peoples obsessed with stats, vs videos (filmed in captivity) and pics
You got "tiger fans" and "lion fans" super engaged at dismiss each other LOL
One of the most bizzarre attitude i ever seen on the internet, wich say a lot
About the lions attacking the bears, my reasoning is kinda simple: when given chance lions attack/kill basically every competitor carnivore in africa be hyenas, leopards or cheetas.
Crocs are an exception and mostly i think because they don't share the same field (ground/water) and are at huge disadvantage in each other camp, so there's not or rarely direct competition
I don't think i ever seen a vid of lion/croc kill each other, at best some tug-of-war next to water or lions harassing crocs out of water but never involved to the point of risk damage (first instinct of wild animals) to kill it
The clash can easily happen in a scavenging situation, imagine the bear bully away AWD/hyneas from a kill and then a group of lions arrive to do the same to him
I'm imagining scavenging scenario because hunt will be harder than his usual habitat: preys are just as fast if not more, and savannah terrain favor runners and long runs with less chances of ambush, specially with his big ass
And in chasing he may be slowed down too, by heat and lower energy (lack of water/food to be in optimal shape)
Bears are crazy tough, but a group of lions will be too much, specially if there's more than one male
Also on big preys they have been seen use a different approach than suffocation (wich is'nt impossible either), males take the back/rear and bite the spine (often with some other attacking the head/throat)
Bear is very strong but not bulletproof like in fantasy internet fights where every animal got borderline superpowers
Even a lioness have the weapons to cause a bear some damage, let alone fierce big males
Cumulative damage is a thing, for how i see it the bear either go away (like in some confrontations with wolves) or end up killed
Plus if lions realize what good source of food the bear can be the clash will get an extra factor, see how tigers already take the risk hunting on smaller/female ones
Last but not last even assuming healthy, heavy, strong, sambo champ bear can truly survive a full clash with a pride of lions (and that's a big if)... how long he will manage to keep that health status?
As you said heat, water and food (even just vegetal) will be far from his usual habitat, chances are he will very weakened in few days... and if i don't like his chances healthy vs a lions pride, a weakened one sound very fucked