A good point was brought up earlier: how to deal with Jynx. In terms of the RU drops' impact, Jynx has had the biggest impact and shaped much of the entire metagame for better or worse(?). Let's compare the influence each RU drop had had on the meta:
Primeape: Compared to Sawk, Ape hits (or unlikley, sets) the important 95 speed tier, but has notably less Attack. The most noteworthy aspect of Ape is that it has U-turn, allowing it to perform hit-and-run antics to escape its counters, while also dealing super effective strikes on Psychics. It also has the nifty Vital Spirit, which grants it the rare privilege of switching into Jynx's Lovely Kiss and threatening her with STAB Close Combat or SE U-turn. However, even with U-turn, Primeape cannot beat much of what Sawk cannot: Ape is still not beating Musharna for days even with the SE move, while Misdreavus, Alomomola, Tangela and Golbat brush off Ape's attacks like nothing. Its most common set, Choice Scarf, allows Ape to revenge kill (slightly) more opponents, but this means Ape's attacks are all unboosted by any item or nature, because doing so means it has to take a gamble with Jynx, who is also a popular Scarfer due to sharing the same speed tier, Lovely Kiss and Trick. If Primeape does not run a Scarf, it loses much of its merit in Vital Spirit since it either speedties or loses to all Jynx as a result.
Overall, Primeape's impact on the meta is not overly prominent when considering the high standard for fast-paced and powerful offense, and can find its place on teams as a fast pivot.
Mandibuzz: The only defensive RU drop, Mandibuzz set a new standard for 'bulky' with her 110/105/95 defenses which are very impressive. Not only that, but she can stallbreak very well with Taunt and Roost combined with that great bulk and usable speed. And she has STAB Foul Play too, meaning she can fight back much better than her competitor Golbat, who shares much of her traits up until this point. While Mandibuzz cannot stop Jynx unless the former is healthy and the latter is not, everything she resists has to adapt or will be stunted heavily. Most Grass-types cannot break Mandibuzz even with the help of Hidden Power, Ghosts and Psychics will have to invest in Thunderbolt if they want to get past the vulture, while Golurk, the most important threat that Mandibuzz beats, have considered the option of more speed to outrun Mandibuzz, though the vulture can simply run a bit more to compensate for that. Mandibuzz is held back by her Stealth Rock weakness and lack of many resists, but can absorb many powerful blows from both end of the spectrum with her raw bulk alone, whilst attempts to stall Mandibuzz (or stopping her from stalling you!) will prove difficult with her access to Taunt+Roost.
Overall, Mandibuzz has had a fairly prominent impact on the tier since she managed to somewhat slow down the surge of hyper offense, and gave more balanced or defensive teams a chance to regain their limelight and helped to stabilize and balance the tier, if ever so slightly.
Scolipede: Great speed, great coverage, acceptable power, an immense movepool and most importantly Spikes makes Scolipede tailor-made for almost any role an offensive team could want, and even managed to fit in some defensive teams. A fast Spiker that can fight back is just what HO teams ordered, as they can quickly set the pace of the match with instant pressure, be it passive or aggressive. Swords Dance sets aim to spam the strongest Bug move in the tier to skewer things hard, and use its impressive coverage to back it up or even try Baton Pass to allow a teammate to sweep when things get tough for Pede. However, even with the potential movesets that can be concocted with Scolipede's offensive and support options, it usually boils down to either Spikes, Swords Dance or even both. There's also the fact that Scolipede is very frail: even bulkier Scolipedes aim to set more entry hazards rather than actually walling threats.If Scolipede's Megahorn is resisted, its unboosted 90 base Attack means its coverage options aren't quite strong enough to bring down the obstacle without risking major damage no thanks to its fraility, meaning the likes of Misdreavus, Torkoal, Golurk, Gurdurr, Garbodor and Braviary are good checks/counters to Pede. As a result, Scolipede does not last very long on the field at all. However, the time a well-played Scolipede does spend attacking can leave quite the dent on your team, no mtter how little moves it pulls off. That kind of move-reward ratio is not to be underestimated.
Overall, Scolipede has a very prominent impact on the tier by paving the way for offense to come steamrolling right through, and is the proponent for popularizing heavy offense.
Jynx: We've talked about her numerous times already, so let's just get to the part on how one deals with her. Here's the thing, she has Lovely Kiss, high power and great coverage. Now when compared to Scolipede, who has had a great impact on the tier but can still be stopped by fairly traditional and standard (not far-fetch'd) sets like Rock Blast Garbodor and Flamethrower Weezing, but Jynx has made the usage of obscure moves or pokemon viable, like Sleep Talk Metang (without Rest), Psyshock Musharna, Scald+EQ Toad, Pursuit Tauros, Vital Spirit Magmar, Sneasel, Hypno, Grumpig, Bronzor, Wormadam-T and the one that crowns them all: Gyro Ball Wartortle. Not to say some of these pokemon are bad, but as an example I'd rather use Gardevoir over Hypno and Grumpig due to access to both Wish and Heal Bell. All of the aforementioned Jynx roadblocks are very uncommon or downright unheard of pre-Jynx, and the fact that these sets exist only proves that Jynx's presence can put quite a strain in teambuilding.
Overall, Jynx has a downright domineering presence on the meta, and basically shaped the meta around herself, be it by setting the speed tier to beat, necessitating the use of an Ice-resist, and packing an measure against sleep all on the same team. Whether Jynx is banworthy is still up for debate, but she is definitely suspect-worthy.