10 Things that can probably switch into Chansey without fear of much is:
Heracross Hitmontop Celebi Sigilyph Suicune Snorlax Roserade Escavalier Xatu Hariyama
I stated that can switch in without fear of status/ stop her from wish passing...
heracross- wouldnt like a t-wave
hitmontop-wouldnt like a toxic nor t-wave unless it has rest
celebi-true on the baton pass part
sigilyph- pretty much allows chansey to heal herself and wish pass to something else..sigilyph needs like 4 Cosmic powers or even 6 before it becoming threatening..i would just heal myself with chansey then switch to my phazer right when you start setting up
Suicine/snorlax-same boat as sigilyph
roserade- yes it does counter all chansey's because it can set up spikes on her without fear, which forces chansey out ..but chansey could always wish to specific counter
escavalier- cant stop from wishing to a counter, but yeah only afraid of t-wave which shouldnt matter for it anyways
Xatu- unless its a 1 on 1 last stand poke xatu gives the opponent waaaayy too much momentum switching in on chansey
Hariyama- rarely used, but yeah forces chansey out to a different counter, but not a threatening set up sweeper
For most of the pokes they are beaten by a simple partner to chansey which is beyond easy to add on a team, i'm looking at dusclops, milotic, or slowbro
@winston-sorry forgot to quote...curse is used for that exact purpose, to force an opponent out..lets say crocune has alot of Calm Minds under its belt, then you send in curse and now its become really difficult for that crocune to stay alive/take hits/ and lose 1/4 life each turn..towards baton pass it carries over..so the opponent is nearly forced to switch out loosing all of their boosts the worked so hard to get :) its actually a very underrated strategy..lol i might start trying it out..yeah murkrow is UU and yeah that is the true best counter to any BP team, with priority haze/taunt/perish song unless you have mental herb to all your BPers to counter taunt...idk about how defensive it could be, even with priority featherdance, but i think thats why its not used as much