For this I'll just be going through each weight class and taking a look at 'mech classes without too many variants to show for them, and trying to see what I can come up with for them.
Light 'Mechs
The Spider! A solid 'mech known for it's astounding speed output and maneuverability- the 'mech only has 5 variants, all hailing from the 5th edition of the model. After scouring the wiki, I've come up with the SDR-7K. Although introduced a bit later than other models, I don't think it's so late as to not being possible.
The SDR-7K most notably provides an ECM hardpoint, and on the stock model- carries just two medium pulse lasers. While this does seem to fill the same role as the 5D, the ambiguity of the 7K could allow for ballistic hardpoints where it's missing laser ones, giving an ECM ballistic variation.
4-JJ
RT- 1E, 1 ECM
LT- 1E, 1 AMS
LA- 1B
RA- 1B
The beloved Raven is most notably known for it's ECM-mounted variant in the Turn-Based Strategy Battletech game. Or at least, that's how I first heard of it. The Ravens we have now don't have really any capability for longer range fire support, but this variant does have that capacity.
The RVN-3M sports more missile hardpoints in order to equip an LRM-15 in its' stock variant, and some quirks could cement it into this role. There aren't many fire support light 'mechs in the game, they're mostly all harassers, so this could be an interesting and unique addition.
LA- 2 E
LT- 2 M
RT- 1 M, 1 AMS
RA- 1 E
Medium 'Mechs.
I have never once seen a Kintaro in a quick play match. I just haven't. It's a, sadly, irrelevant 'mech with not much love from the playerbase. I think adding some much needed versatility to the 'mech would give it a much-needed revitalization.
The KTO-K is a lesser-known variant of the Kintaro which is built for a brawling and skirmishing role. The most significant addition to this variant is Jump Jets, which obviously increase the maneuverability of the 'mech quite a bit. It's an upgrade to the KTO-20, and the stock variant removes the LRM and Large Laser to upgrade the SRMs to Streak SRM-6s. Additionally, it comes with 3 ER Medium Lasers. This would provide what I believe would be an honestly fun experience with the Kintaro.
4-JJ
LA- 2 E
LT- 3 M
RT- 1 E, 1M
RA- 1E
I've also seen little use of the Vindicator as well, and it only has 5 variants to be obtained.
The VND-4L is a later edition of the Vindicator which comes with a Guardian ECM and Stealth Armor. The stock variant has an ER PPC, an LRM-5, and two medium lasers- one ER and one Pulse. It also has double heat sinks. Giving the Vindicator an ECM variant would allow it to transition into the sort of 'lone wolf sniper' variant its' design so eagerly wants it to do.
4-JJ
LA- 1E
LT- 1 M, 1 ECM
RT- 1 M, 2E
RA- 1 E
Heavy 'Mechs.
The Dragon has many issues keeping it from greatness, most notably its' awful central torso hitbox and vulnerable arms carrying the only solid weapon hardpoints on it.
The DRG-2Y, Yoroshi's personal battlemech during the Third Succession War Invasion of Galtor III is unique in that it removes all ballistic hardpoints of the other variants to give it only energy and missile hardpoints, this could provide an interesting long range sniper/fire support Dragon and solve the issue of it's hitboxes by just keeping the whole thing out of harm's way entirely. With some fancy quirks, it could be a force to be reckoned with.
LA- 2 E
LT- 1 E
CT- 1 M
RT- 1 E, 1 M
RA- 2 E
The Archer, while it's used plenty often, only has 4 variants. I think some sort of ballistic variant, although it doesn't exist in lore, with torso-mounted ballistic weapons either replacing or joining the missiles- just moving the missiles to the arms- could be pretty interesting, especially if it had quirks to sport.
LA- 1 M, 1 E
LT- 1 B
RT- 1 B
RA- 1 M, 1 E
Assault 'Mechs
Assaults, in my opinion, are in a pretty good spot in Mechwarrior Online at the moment. Almost all of them are viable, and they all have pretty unique roles and fill spot nicely in a trio of Lances. So these suggestions are mostly just that, suggestions based on what I think would be cool.
The King Crab. It's my favorite 'mech in the game, and while the KGC-005 is what many people are asking for, I personally think another variant would provide a much more unique role and perspective to the 'mech that the playerbase would enjoy.
The KGC-008 is a long-range fire support mech with a pair of Autocannon 2s and two Heavy PPCs located in the arms. Two Torso-mounted ER Medium Lasers are mounted as well, and the design keeps its' LRM-15. The unique part about this 'mech is it's also designed to support its' allies, with a Guardian ECM suite located in it's Torso as well. The maneuverability of this 'mech is nothing to be scoffed at either, as the thing can even equip Jump Jets, which would be the first of the King Crabs to do so.
4-JJ
LA- 1E, 1B
LT- 4 E, 1 AMS
RT- 1M 1 ECM
RA- 1E, 1B
Lastly, simply due to lack of representation, the Charger makes this list too. it's a very unique and beautiful assault mech known for it's namesake.
The CGR-2A2 is a variant of the Charger which sports a medium laser and five rocket launcher 10s, which means it has at least five missile hardpoints. This definitely gives the variant a unique role within it's model
LA- 1 E
LT- 2 M
RT- 3 M
RA- 1 E
Although this list is ALL Inner Sphere 'mechs, I think the existing clan 'mechs are all in a good spot, and rather than adding new variants of clan 'mechs they should just start adding entirely new clan 'mechs to the game, if possible.
And although you're not looking for entirely new models of 'mechs, I personally am a huge fan of quadrupedal 'mechs, and I do think the Scorpion, SCP, and the Goliath, GOL, would be nice additions and a good introduction to the world of quadrupedal 'mechs in Battletech, represented in MWO. Just a suggestion. Thanks for reading!
Edited by SedentaryScorpi, 20 January 2021 - 12:30 PM.