The only fatal dog attacks in the UK involving Jack Russells are
- 2012, 8 day old baby, Jack Russell crossed with something unspecified
- 2009, 3.5 month old baby - but there was also a Staffordshire bull terrier involved
- 1986, 5 day old baby
There are zero deaths, ever, in the UK involving either dachshunds or Pomeranians.
That's 3 deaths over almost 40 years, all involving very tiny, delicate babies who, to be blunt, don't take much effort to kill.
In the last 12 months alone, there have been 4 deaths involving an XL Bully, 2 involving the closely related American Bulldog, and 2 more recent ones involving an unconfirmed breed. All but one of the victims were adults.
There are small, feisty breeds which are entirely capable of drawing blood, but there's no way they're capable of bringing down an adult and nor are they frequently killing children.
Source: https://en.m.wikipedia.org/wiki/List_of_fatal_dog_attacks_in_the_United_Kingdom
The OP is being ridiculous, but you are also being ridiculous if you seriously think Jack Russells are as much of a danger to children as XL Bullies.