I assume that you're after a strategy to beat Clay with what you have, rather than backtracking for more advantageous Pokémon. I like doing things the hard way too, so let's see what we can do.
Pidove may be the best lead for Krokorok, and I suggest giving it that rocky helmet; Tepig won't need it here. Crunch makes direct contact whereas Bulldoze and Rock Slide do not. (Since Lillipup is useless here, you could try risking attract here if it's female.) Spam Air Slash and hope for the best. Would it outspeed a level 29 Krokorok at level 33?
You'd want to bring in Purrloin at full health to take on Palpitoad, which means staying with Pidove until it faints, or possibly sacrificing Lillipup as well. (Tepig can also learn Grass Knot but it's a risky play.) There's not much power, but 4x always hurts. Ducklett can help if necessary since it resists water and is immune to ground.
Excadrill has Rock Slide for flying type coverage. Can your Blitzle outspeed it? You might be able to get lucky with Flash. If you can take its accuracy down, you have better odds of evading attacks, especially Rock Slide. If you can get it on a clean switch, Lillipup's attract could also be employed here, again if it happens to be female. Ducklett would have to spam Bubblebeam and evade rocks, Tepig's flamethrower should do good damage but Bulldoze and rocks will cripple it. Those two are really your only offensive options here, so if you can tweak the odds with status moves, it may help.
You may need a little luck, but it doesn't look impossible.