You could trade the darkness traps at north and east for a single str drain that covers both north and east if your radius is big enough. Also you should be able to get away with less reflector beams with carefully placed anti spider proxi and magic barricades. Just to let you know, spiders prioritize magic barricades over towers so well placed barricades and proxi could take care of all spiders completely without u spending so much du on reflectors. I also don't see much point of having both darkness and str drain west. If your ev walls have enough hp to tank you could try with just darkness but if your having trouble taking to much damage just keep str drain. I would just keep str drain that way the wall doesn't have to be watched as much.
I would keep the proxi traps at north and south because of sharkens, but you might be able to get away without proxis east and west and just move the snare auras on top of the gas traps. Ensare auras don't need to placed on buff beams sometimes people place snares way farther back then they could be just so they are buffed but thats mostly unnessicary, snares have a hard cap at 15% movespeed and you reach that cap with only 1200 tower damage without being upgraded so they are much more effective farther forward companied with a gas trap to slow down the creeps and Sharkens.
the reason i have darkness auras at every corner is because once congestion sets in and mobs get held back, a good number have poision resists, and with a serpent, that kills its useful ness, so getting that as soon as possible is a must
the reason there is a str drain in the west is because of spiders on the side that can be poison resist and because that baracade itself is only 2du, the smallest one of them all, and i don't want to babysit that corner.
my st drain aura isnt big enough to cover the north and east without a 3 star buff beam and even than its barely big enough. and even with that, from what i have seen with the sharks in the east, if they get any closer in the east, they will charge, so i have to have the darkness there.
the reflect beams are placed last, and are left over du and they are there as much for spiders as they are for ogers on later waves, even what i was able to get to 23, ogers were able to take my squires harpoons down to the sub 25% range more than once.
also the one ensnare on a buff beam would get hit by that buff beam regardless, as i place them so they cover the baracades.
the mane problem i have is that after wave 19, wyrven are able to get in on the east, and i use to be on repair detail exclusively after wave 18, not im running around being primary dps due to sharks, that wave 20 is hard if not impossible for me to pass due to oogers taking down baracades...
and even if i used a st drain for the north and east i have the problem of it drying out way to fast due to how i congest the mobs.
yea, if i use the apprentance harpoons, they definalty do damage, however when i factor in the fire splash damage, and the fact most the the enemies here are barely able to be hit by the splash much less a direct harpoon.
pre shark this setup was doable with harpoons, but post, i need all the traps, and harpoons would set it back by about 14 more du.
on the builder my stats are about 1400 all around, with range being about 1100
waller is 1900 hp and mid range other stats
on all other characters assume about 1000 for all stats, some are higher, some are a bit lower, but about 1000 for all.