All-Grain w/ Two SS 40Q Kettles

I have two Bayou Classic 40Q (10G) Stainless Kettles, each with 1/2" spigots. I plan to upgrade one with an integrated thermometer and domed false bottom. That would be my MLT and the other my Boil Kettle.... or so I presume. Can I make the move to AG using just these two kettles? My thinking was to heat sparge water in the boil kettle on one burner and mash in the MLT on another burner. Once I was done sparging, couldn't I then collect my wort in the empty boil kettle and proceed to boil? Maybe I am misunderstanding the AG process but do I really need a 3rd vessel? I’d like to stick to these two pots if there’s a reasonable way to do so. PS. I do have other much smaller stainless pots (roughly 2G) that maybe would work for heating sparge water if needed. Thoughts are appreciated!

I do AG with a cooler mash tun and a 10G brew kettle. I used the kettle to heat the sparge water and then I use extra 5g buckets to store hot water when I do multiple batch sparges. Unless you're fly sparging, I see no strong reason to have 3 kettles, and even if you are fly sparging, you can make do with 2 kettles and an extra vessel

I have since purchased a second Bayou Classic 40Q (10G) Stainless Kettle and a 5 Gallon Igloo Beverage Cooler. I have spigots installed on all of them and am now hoping the Igloo is a big enough mash tun for 5G AG batches. Most of what I read says it'll be fine for now. I suppose I could always use it as a HLT and turn one of the 40Q kettles into a mash tun. I wonder what would be a better idea???