It is not bad or incorrect. Your post, however, is wrong and incorrect on many levels.
this is why my first piece of advice to OP is get a solicitor.
the truth is the system is notoriously bad to predict. Even solicitors aren’t sure how a judge will decide to divide assets.
I am specifically referring to divorce negotiations. You are right he can’t be forced to take the kids- but when he realises it weakens his financial position, he may fight for that. So OP has to prepare for a number of scenarios- either way she can negotiate to make sure she has some respite.
as they are married, she has a lot of financial protection. And so do the children of the marriage.
scenario 1- he doesn’t want the kids at all. Great: OP can negotiate and obtain through courts a very favourable financial settlement. She could even ask for a lump sum up front to cover costs until the kids are 18. This can factor in costs like share of childcare to enable her to work/ take time off.
scenario 2- he gets wise to court system and realises that if he asks for kids more, he might get a bigger share. this is also positive for OP, as he will have to take the kids on set days agreed in a court order.
the key thing is the OP needs a court order for both children and financial agreement. These court orders are enforceable. And OP can speak to a solicitor who will tell her how to cover the possibility he will claim he wants 50/50 then walk away. A good solicitor will be wise to this tactic and work out a method of protecting OP.