How to spend dust now?

With raid bosses that are borderline solo-able, it seems like a very strong case to boost pokemon over level 30 with the contingency plan of taking them down solo if needs be:

Here are some of my attackers that I do use on a regular basis, and most would consider them first rate for their purpose or a close second, would you boost them further? Or is a team of 6 counters of level 30 more optimal?

Dragonite DT/H (91 IV) Level 31
Dragonite DB/DC (40 IV with 15 attack) Level 31
Dragonite SW/DC (98 IV) Level 31 <You may assume this is the next one I use a fast TM on
Snorlax L/HB (87 IV) Level 30
Tyranitar Bite/Crunch (89 IV) Level 30
Rhydon MS/EQ (96 IV) Level 30
Rhydon MS/SE (91 IV) Level 36.5
Machamp Counter/Dynamic Punch (98 IV) Level 30
Vaporeon WG/HP (76 IV, 15 Att) Level 30
Vaporeon WG/HP (69 IV, 14 Att) Level 30<This has higher CP actually lol
Exeggutor Conf/Solar Beam (93 IV), Level 30
Espeon ZH/FS (91 IV), Level 30
Flareon FS/OH (82 IV), Level 30
Gengar Shadow Claw/Shadow Ball (98 IV) Level 30
Golem RT/SE (91 IV) Level 30
Jolteon TS/TB (80 IV) Level 30

You may assume that I have a stock of at least 30 candy for each of these.

This also pretty much exhausts all my attacker list. If I only list one jolt for example that's the only good jolt I have (unless you count volt switch/thunder is a good one)