Bug / Dragon:
This typing offers an incredibly unique stab combination, threatening a huge variety of pivots for SE damage, while still being a very limited and fair typing; its got tons of resists to electric, water, fighting, ground, and others, but at the same time its also weak to SR, and only neutral to fire, while having definite holes in its stab combination. This is definitely a very targeted and fair typing.
Bug / Electric:
This typing again offers a great mix of resistances to a specific set of pivots (Zeraora especially, Rillaboom) and very relevant SE hits vs defensive pivots (Slowking, Toxapex, Mandibuzz) making it very targeted to the concept at hand. At the same time it keeps the same SR weakness, and a very notable fire weakness. This is a targeted and fair typing.
Dark / Electric:
This typing targets the Slowtwins, Dragapult, and a number of other defensive pivots. With access to a number of very strong STAB moves, great offensive coverage, and targeted and relevant resistances, this typing is relevant to the concept, and has seen broad support in the thread.
Electric / Fighting:
In contrast to Electric/fairy, this typing offers perhaps the best offensive coverage on this list, targeting the steel/grounds that are often used to absorb Electric hits, while still having a very relevant defensive typing, providing a valuable electric/dark resistance combo. While weak to Future Sight, this typing is still incredibly competent offensively.
Fighting / Psychic:
This typing is a distinct take on the concept, dodging the Slowbrothers in favor of taking on Chansey, many of the offensive options, Amoonguss, and Libra at one time, which is something few of the other options here offer. While it does lack in terms of resistances, it also lacks in weaknesses, which offers the potential to tool this mon to take on most of the offensive pivots if needed.
Grass / Ice:
This is overall the most targeted typing on this list, being almost tailor made to take on the combination of Slowking, Amoonguss, Krilowatt, and Mandibuzz, and not much more, which is a definite plus. This typing is the most targeted in the list, and that is a very good thing, as it leaves the rest of the design process very open. There are concerns about this mon being targeted by 4x coverage, and knock off, but the offensive prowess and targeted resists make it an excellent choice.
Grass / Water
This typing came up late in the game, but is excellently targeted towards Slowking, Equilibra, and Krilowatt, three pokemon that are all very common pivots. It generally lacks resistances outside of those specific pokemon, but it also lacks weaknesses, which means it is a very blank canvas for us to design around. Because of its targeted matchup against these prominent pivots it made this list.