Hmmmmmn, now let the imagining commence... *Tadaaaa*
Like I mentioned before in Fishie11's 'Why have the Outsiders been banned?' topic, page two, on the TLK-2SP discussion board;
Regarding Kopa he might have survived the Crocodile invested river, tumbling into the water, whilst exploring the far corners of the kingdom, due to his everlasting curiousity. And because of the croc-incident he was severely handicapped, just able to survive on his own, until he and Mheetu took over a pride of their own, where Mheetu provided the strength, and Kopa the brainpower of the duo.
Also as I already envisioned in my above-mentioned reply to Fishie11's topic: I highly doubt Zira was the one who'd mauled Kopa. Why? Well we all are witnesses to the given fact that both cub Kovu ánd Kiara went through that same river being attacked by a bunch of hungry crocodiles themselves.
I feel this might have been a silent testemony to what could have happened to Kopa earlier on in the TLK Universe's timeline.
Yet obviously the royal family labels Zira as a scapegoat to blame, due to her close ties with Scar and his former regime.. Also the alledged kidnapping of Shetani (who is later on whilst producing TLK-2 renamed Vitani, yet a glitch in the final recording resulted in Nala calling Vitani by her original name: Shetani (meaning Devil!) just before the two were locked in combat, as Vitani jumped from a rock onto the surprised yet skillfull Nala below.
This glitch clearly left open a wide variety of fanfictions and fanart being produced about this seemingly missing link even up to voices talking about Shetani/Vitani being Nala's younger distant relative incase Shetani/Vitani truly was conceived by Scar. Scar already could have been a potential rival to Mufasa's rule, since he defied his brown maned brother. eventually leading up to actually killing his own brother in the Stampede scene.
An instinct-driven plot would be possible because it isn't solemnly the dominant male who gets to do all the mating, often the comradery between males who recently had taken over a pride, or leading them for several seasons - More often then not tends to changing from friendly into sheer rivalry when it comes to lionesses filling the males' minds.. Ending up in both or all males involved in the mating rituals.
Sometimes it's never clearly known who'se the real father of any given lion cub. The mating normally takes up to four days and nights in a row, but can be disrupted if any potential rival appears on the scene. In the end, not the lions, but the lionesses decide whom they wanted to mate with.
With this in mind, I do not think of Vitani being in love with Kopa, not unless it's another plot made up by the ever vengefull Zira, who just waited to get a chance at speeding up Simba's demise. I don't think that a cub Kopa was portrayed as, would match the personality Vitani had in her cubhood, or even in her elderly years as seen in the movie. I also doubt that Vitani later on dissappeared from the Pridelands to go out and search for Kopa, as lionesses usually prefer the safety of an established pride over wandering around on their own.
Young lions can play toegether with one another, but unlike humans, they don't have the emotions humans tend to have when it comes to actually loving one another, over instinctively trying to survive together.
Now as for Mheetu, I'll also stick to the idea he was attacked by Scar's minions, but in my opinion he could barely kill one of his pursueing assasins, before he could manage to escape. Remember, a cat in danger can perform some rare tricks to escape!
Now I foresee the Hyena trio as the shocktroops Scar employs to his more sinister deeds, whilst the greater amount of the Hyena's were just surpressing the Pridelanders stealing kills, and that the Outlanders to be, kept the Hyena's at bay whilst tugging dinner into Scar's cave enjoying the left overs after their king was done eating. The Outlanders were also being around fending off any eventual uprising directed against king Scar, and especially being protective of Queen Zira whom the Outlanders pledged their loyalty to.. Whereas it is clear to see that the Hyena's stick to Scar's policies.
Mheetu on the other hand, might have lived to see his own cubs being born, in a neighbouring pride where he'd managed to take over with the help of fellow rogues - Just like most matured male lions tend to do, when they're expelled from their native prides. And plotwise, it is more interesting if both Mheetu and Kopa survived their ordeals, perhaps to one day meet up together settling down as both males were guaranteed to have been cared for by their loyal lionesses in their own pride.
So that's my little addition to the matter. I hope this satisfies your needs for different opinions regarding your question TG! * Goes hugging the crap out of his mate TG*