I'd ditch the workbooks too, tbh, unless you can see a clear benefit to them. Don't do them for the sake of it! Workbooks can be really really useful at higher levels but I suspect most 5 year olds have more importnat stuff to do
ok what I'd do is work out what, if anything, you really really want them to know. ditch anything non-essential.
And ask them, esp your 5 yo, what he really wants to know. Also ask him how he wants to learn, how he thinks he learns best, etc. He will probably suprise you!
And then find ways of letting them learn it, or teaching it, that can include all the children.
So in our house, at the start of the year ds really wanted to learn more about chess, telling the time, knitting, music and cooking (among other things). I have ds, (5), dd1 (3) and dd2 (7 months)
These are all things requiring quite a lot of maths, and in some cases, reading. They've also spun off into history, geography, biology, etc.
We just do the activities and everyone has a turn at weighing, counting, sounding out the words etc. Ds is of course right more often than dd1 but everyone is happy.
I keep a weekly log of activities, question, observations etc and am always quite smug looking back at how much has clearly been learnt.
the only tips i have re table type work is, if he needs 1-1, do it while your partner is home, if not, get him his own desk in the main room of the house. ds has a little desk in an alcove for his electronics and drawings and so on and he loves it, he spends quite a lot of time just sitting there pondering.
Oh and obviously, if you haven't already, buy a sling.