CLIFFNOTES: It is never ever ever wrong getting our money in when we have the nuts. No matter when, no matter the street, no matter the number of opponents!!!!!
Period!
However, with that being said, lets take a step back and think through this spot.
What range of hands do we assign our villain given the action?
The most probable hand in our villains' ranges are flush draws. Sets and 2p combos and pair+SD and pair + FD combos are also definitely in our villains ranges.
the question we need to ask ourselves in regard to shove now vs shove later is if there are cards that can kill our action? and if so, what is the likelihood of those cards coming. Another consideration is pot commitment, usually we will want to raise as early as possible with the nuts so we can build a pot that commits our villains to stacking off later or such that we can extract more value on later streets.
Dealing with the commitment reason first, since our villains put in half their stack, they are committed and thus will have to call the turn shove no matter what.
So now we are back to the first reason, scare cards. In this case, the scare cards apply to us
If turn is a spade are we folding?
If turn pairs the board are we folding?
The answer really lies in our confidence of either V having a flush or set...
Here is the problem with soul reads in this spot. The problem is that our villains have a RANGE of hands here and a spade on the turn doesn't automatically mean we lose nor does the board pairing automatically mean we lose. Our villains can have 85 here or pair + straight draw like 98 or 87... So what this means is we end up folding the best hand in spite of a spade hitting on the turn or the board pairing...
I know in our heart of hearts we feel we can soul read our villains for a flush draw but you would be amazed how often they show up in this spot without it. So now the mathematical question simply becomes, do they show up enough in spots like this without the flush draw for us to be mathematically incorrect in folding if a spade shows up?
ahhhhhh therein lies the rub.
If you were to do an EV calculation of this scenario and if you were 80% confident that V is on a flush draw and if a spade hits on the turn you fold, what you will discover is that overall you don't save that much money and in fact lose money long term.
You would have to be right like 90%+ of the time that V is on a flush draw so that you could fold this turn when a spade hits.
Then factor in the times you fold when the board pairs and V's are on some combo draw that you still beat...
The EV calculation starts to branch out geometrically in terms of % they have the have vs % of times you guess right vs % of times you guess wrong...
but when the dust clears, the end result is very simple.
WHen you have the nuts, the most optimal line you can take in spots like this when SPR < 2 is to just shove. No ifs ands or buts about it.
IN this spot, shove, and ride the variance train.
It is never ever EVER EVER EVER wrong to get all your money into the pot vs any number of villains when you have the nuts.
I did a model awhile ago of someone having AA preflop vs 1, 2, 3, 4.... villains to prove to everyone that +EV is +EV and if you get your money in while ahead that is the +EV line no matter what... see if I can't dig that thread up...