Im surprised they didnt add in lots of births as one of your risk factors too, from baby #5 they get quite antsy about you being a "grand multipara" and at risk of bleeding after the birth so they want to put all these plans in place.
If you are happy with what they think then i would just go with the flow, if you aren't then i would ask more questions .
I'm a high risk pregnancy, but i have been from #1 so havent known any different and have been happy with being monitored more closely anyway, its reassuring for me, however i do understand that its not for everyone .