In the clip Kevin posted you see things that make no sense from a Judo perspective, but BJJ rolling and Judo randori are different games.
OTOH, there are similarities between bjj and aikido, but they are not evident in the sense of "techniques" (you are not going to see shihonage or ikkyo pins in bjj). The similarities are more in the flowing, movement, management of forces, relaxation...
Judo has the same concepts in Ne Waza , ie Tori should be relaxed , he should neutralize the movement of Uke, where required Tori has to manoeuvre /be prepared to change his position in response to ukes defence strategy.So as you say you will not see shihonage in judo/bjj. Since judoka are rarely pinned down, face down,check out Judo newaza Kata, ikkyo is unlikely to be applied.If a judoka turns his back on Tori , the usual primary strategy is to use shime waza.eg okuri eri jime, hadaka jiujime.Possibly M.M.A/B.J.J would use the naked strangle [hadaka jiujime]if no jackets were worn by the combatants??? Cheers, Joe.