Well as someone who hasn't beaten the game yet, I can safely say that I'm not stuck in a rut. Let me share to you a story of how I worshiped certain god's yet managed to adapt to the drops that I got:
So let me begin with an octopode wizard of sif muna. Wizard is probably the best spellcaster to play the adaptive playstyle you talk about. So, my typical wizard build is to level my summonings to level 5 and to level conjurations until I max out magic dart. Then, I begin to prioritize conjurations once I get a spellbook with some good conjurations spells in it. Unfortunately this time, I didn't. I ended up getting book of summonings first. Believing it to be a priority to start training high tier spells as soon as possible, I decided to begin dumping xp into the summonings skill. From then on, I was getting more and more summoning books until I had every summoning spell in the game. Then I got a book with some conjuration spells in it. Immediately, I abandoned summoning and started dumping xp into conjurations instead. Conjurations then became my go to playstyle, I abandoned summoning only using it as a panic button. Eventually, I got the demon ending in swamp. There, I had to face foes too powerful for my conjurations. They also made quick work of my monstrous menagerie minions (my most powerful summoning spell I had memorized). That was where I died
As you see, you can adapt to the RNG with certain gods. Perhaps not all of them, but you mentioned sif muna as being one of the gods with which you couldn't. You don't give her enough credit. The spells she gives are very random, possibly forcing you to adapt if you're unlucky enough. I also have a story of an ice elementalist that was turned into a necromancer but seeing how long it took to type the octopod story, I would rather not type a wall of text again.