Golem with Rapid Spin seems like it could have a decent niche if it kept Rapid Spin, as it could work well on offensive teams with Explosion to blow a hole in teams, but would that be enough to have use over Donphan?
It would propably not be very good. Reasoning 1. It loses one on one againt common spikers like Toxic Skarmory, Toxic Forretress and Cloyster. 2. It gets spinblocked by Gengar easily. Gengar can come in Earthquake and burn it with Will-o-wisp, hit hard with Ice Punch or even one-hit KO with Giga Drain. 3. It does not really have anything going for it compared to Claydol. Claydol is faster, has a much better defensive typing, has ground immunity, can hit Gengar super-effectively and can have 270 speed without enough investment, letting it outspeed base 85s with max speed and speed-neutral nature like Suicune and Heracross. 4. It has a horrible defensive typing. It is weak to Earthquake, Focus Punch and Ice Beam and gets one-hit KOed by a single HP Grass or any water type move. This means it is frail inspite of its high defenses on paper. The 4x grass weakness is especially crippling because most offensive Pokemon carry HP Grass to deal with Swampert. Source: Personal experience playing Gen 3 OU
