I recently retired and with surplus funds want to do SIP and then SWP

Please note that both the funds in your selection are diversified equity funds and have long track record of consistent performance. Both the plans offer SWP feature.

However, 20 month is not the adequate time period for doing SIPs in diversified equity funds. The horizon should be minimum 48-60 months.

Your idea of accumulating a corpus by investing systematically and then doing SWP is a good one! But the period of 20 months for investing in diversified equity funds is too short. If the markets are not doing well during this period then opting for SWP without adequately building a corpus may not work for you. Therefore, you should have a longer horizon.

The other idea of withdrawing 1% per month is also little ambitious. We think withdrawing 0.75% - 0.80% monthly thru SWP should be okay. Again increasing the annual withdrawal by 5% should be the target as 10% is quite high!

Having said that, everything will depend upon how the market situation is when you start the accumulation and start the SWP. But definitely, having a longer horizon for accumulating the corpus through SIP will be the key of this investing strategy.